DecimalFormat继承自NumberFormat，可以使用它将十进制的数以不同形式格式化为字符串形式，可以控制前导和尾随0、前缀、后缀、分组（千）、小数分隔符等，如果要更改格式符号（例如小数点分隔符）。
它有各种各样的设计使其能够解析和格式化数字的特征区域设置，包括对西方、阿拉伯和印度数字的支持。它也支持不同类型的数字，包括整数（123），定点数字（123.4），科学符号（1.23 e4），百分比（12%），以及货币金额（123美元）。所有这些都可以本地化。
可以将其DecimalFormatSymbols与DecimalFormat类一起使用。这些类在数字格式化方面提供了极大的灵活性，但它们可以代码更加复杂。
包：import java.text.DecimalFormat;
构建模式
使用DecimalFormat模式指定格式设置String的模式属性pattern：
DecimalFormat df = new DecimalFormat(pattern);
关于pattern，有：
数字格式模式语法
可以按照以下BNF（巴科斯范式）图表指定的规则为数字设计自己的格式模式：
pattern： subpattern {; subpattern}
subpattern（子模式）： {prefix} integer {.fraction（分数）} {suffix}
prefix(前缀)：'\\ u0000'..'\\ uFFFD' - specialCharacters
suffix(后缀)：'\\ u0000'..'\\ uFFFD' - specialCharacters
integer：'＃'*'0'*'0'
分数： '0'*'＃'*
上图中使用的符号如下表所示：
| 符号 | 描述 |
|---|---|
X* |
0个或更多个X实例 |
(X | Y) |
X或Y |
X..Y |
从X到Y的任何字符，包括在内 |
S - T |
S中的字符，除了T中的字符 |
{X} |
X是可选的 |
模式中的特殊符号：
| 符号 | 描述 |
| 0 | 一个数字 |
| # | 一个数字，0显示为缺省（即空字符） |
| . | 小数点 |
| ， | 分组分隔符 |
| E | 指数表示的底数指数分隔符 |
| ； | 分隔格式 |
| - | 负号前缀 |
| % | 乘以100并显示为百分比 |
| ？ | 乘以1000并显示为千分比 |
| ¤ | 货币符号; 用货币符号代替; 如果加倍，用国际货币符号代替; 如果存在于模式中，则使用货币小数分隔符而不是小数分隔符 |
| X | 任何其他字符都可以在前缀或者后缀中使用 |
| “ | 用于引号前缀或后缀中的特殊符号 |
示例：
value | pattern | output | 说明 |
|---|---|---|---|
| 123456.789 | ###，###。### | 123,456.789 | 井号（＃）表示一个数字，逗号是分组分隔符的占位符，句点是小数分隔符的占位符。 |
| 123456.789 | ###。## | 123456.79 | 将value有三个数字的小数点右边，但pattern只有两个。该format方法通过四舍五入来处理这个问题。 |
| 123.78 | 000000.000 | 000123.780 | 的pattern指定前导和尾随零，因为0字符被用来代替井号（＃）。 |
| 12345.67 | $ ###，###。### | $ 12,345.67 | pattern美元符号（$）中的第一个字符。请注意，它紧接在格式化的最左边的数字之前output。 |
| 12345.67 | \ u00A5 ###，###。### | ¥12,345.67 | 在pattern与Unicode值00A5指定为日元（¥）货币符号。 |
1 DecimalFormat df = new DecimalFormat("000.###");
2 String s = df.format( 1.11111);
3 System.out.println(s);
4 //output: 001.111
5
6 df.applyPattern("000.000"); //重新应用新的模式
7 System.out.println(df.format(1.11111));
8 //output: 001.111
9
10 df.applyPattern("000E000");
11 System.out.println(df.format(1111111));
12 //output: 111E004 (1111111 约等于111 X 10^4)
13 df.applyPattern("0E0");
14 System.out.println(df.format(1000000000));
15 //output: 1E9
16
17 df.applyPattern("###,###,###.###");
18 System.out.println(df.format(11111111.11));
19 //output:11,111,111.11
20
21 df.applyPattern("0.0%");
22 System.out.println(df.format(0.1));
23 //output: 10.0%
24
25 df.applyPattern("sd.00"); //可添加其他常规字符
26 System.out.println(df.format(0.1));
27 //output: sd.10
区域敏感格式
前面的示例DecimalFormat为默认值创建了一个对象Locale。如果您想要一个DecimalFormat非默认对象Locale，则实例化a NumberFormat然后将其强制转换为DecimalFormat。这是一个例子：
NumberFormat nf = NumberFormat.getNumberInstance（loc）; DecimalFormat df =（DecimalFormat）nf; df.applyPattern（图案）; String output = df.format（value）; System.out.println（pattern +“”+ output +“”+ loc.toString（））;
运行上一个代码示例将导致后面的输出。格式化的数字位于第二列，具体取决于Locale：
###，###。### 123,456.789 zh_CN ###，###。### 123.456,789 de_DE ###，###。### 123 456,789 fr_FR
到目前为止，这里讨论的格式模式遵循美国英语的惯例。例如，在模式###，###。##中，逗号是千位分隔符，句点表示小数点。如果您的最终用户没有接触到它，那么这个约定很好。但是，某些应用程序（如电子表格和报表生成器）允许最终用户定义自己的格式设置模式。对于这些应用程序，最终用户指定的格式模式应使用本地化表示法。在这些情况下，您将要调用applyLocalizedPattern该DecimalFormat对象上的方法。
改变格式符号
您可以使用 DecimalFormatSymbols类更改format方法生成的格式化数字中出现的符号。这些符号包括小数分隔符，分组分隔符，减号和百分号等。
下一个示例DecimalFormatSymbols通过将奇怪的格式应用于数字来演示该类。这种不寻常的格式是调用的结果setDecimalSeparator，setGroupingSeparator和setGroupingSize方法。
DecimalFormatSymbols unusualSymbols = new DecimalFormatSymbols（currentLocale）; unusualSymbols.setDecimalSeparator（ '|'）; unusualSymbols.setGroupingSeparator（ '^'）; String strange =“＃，## 0。###”; DecimalFormat weirdFormatter = new DecimalFormat（strange，unusualSymbols）; weirdFormatter.setGroupingSize（4）; String bizarre = weirdFormatter.format（12345.678）; 的System.out.println（奇异）;
运行时，此示例以奇怪的格式打印数字：
1 ^ 2345 | 678date：2018-10-31 12:57:51参考：https://docs.oracle.com/javase/tutorial/i18n/format/decimalFormat.html#numberpattern附DecimalFormat类源码：
1 /*
2 * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
3 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
4 */
5
6 /*
7 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
8 * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
9 *
10 * The original version of this source code and documentation is copyrighted
11 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
12 * materials are provided under terms of a License Agreement between Taligent
13 * and Sun. This technology is protected by multiple US and International
14 * patents. This notice and attribution to Taligent may not be removed.
15 * Taligent is a registered trademark of Taligent, Inc.
16 *
17 */
18
19 package java.text;
20
21 import java.io.IOException;
22 import java.io.InvalidObjectException;
23 import java.io.ObjectInputStream;
24 import java.math.BigDecimal;
25 import java.math.BigInteger;
26 import java.math.RoundingMode;
27 import java.text.spi.NumberFormatProvider;
28 import java.util.ArrayList;
29 import java.util.Currency;
30 import java.util.Locale;
31 import java.util.ResourceBundle;
32 import java.util.concurrent.ConcurrentHashMap;
33 import java.util.concurrent.ConcurrentMap;
34 import java.util.concurrent.atomic.AtomicInteger;
35 import java.util.concurrent.atomic.AtomicLong;
36 import sun.util.locale.provider.LocaleProviderAdapter;
37 import sun.util.locale.provider.ResourceBundleBasedAdapter;
38
39 /**
40 * <code>DecimalFormat</code> is a concrete subclass of
41 * <code>NumberFormat</code> that formats decimal numbers. It has a variety of
42 * features designed to make it possible to parse and format numbers in any
43 * locale, including support for Western, Arabic, and Indic digits. It also
44 * supports different kinds of numbers, including integers (123), fixed-point
45 * numbers (123.4), scientific notation (1.23E4), percentages (12%), and
46 * currency amounts ($123). All of these can be localized.
47 *
48 * <p>To obtain a <code>NumberFormat</code> for a specific locale, including the
49 * default locale, call one of <code>NumberFormat</code>'s factory methods, such
50 * as <code>getInstance()</code>. In general, do not call the
51 * <code>DecimalFormat</code> constructors directly, since the
52 * <code>NumberFormat</code> factory methods may return subclasses other than
53 * <code>DecimalFormat</code>. If you need to customize the format object, do
54 * something like this:
55 *
56 * <blockquote><pre>
57 * NumberFormat f = NumberFormat.getInstance(loc);
58 * if (f instanceof DecimalFormat) {
59 * ((DecimalFormat) f).setDecimalSeparatorAlwaysShown(true);
60 * }
61 * </pre></blockquote>
62 *
63 * <p>A <code>DecimalFormat</code> comprises a <em>pattern</em> and a set of
64 * <em>symbols</em>. The pattern may be set directly using
65 * <code>applyPattern()</code>, or indirectly using the API methods. The
66 * symbols are stored in a <code>DecimalFormatSymbols</code> object. When using
67 * the <code>NumberFormat</code> factory methods, the pattern and symbols are
68 * read from localized <code>ResourceBundle</code>s.
69 *
70 * <h3>Patterns</h3>
71 *
72 * <code>DecimalFormat</code> patterns have the following syntax:
73 * <blockquote><pre>
74 * <i>Pattern:</i>
75 * <i>PositivePattern</i>
76 * <i>PositivePattern</i> ; <i>NegativePattern</i>
77 * <i>PositivePattern:</i>
78 * <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
79 * <i>NegativePattern:</i>
80 * <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
81 * <i>Prefix:</i>
82 * any Unicode characters except \uFFFE, \uFFFF, and special characters
83 * <i>Suffix:</i>
84 * any Unicode characters except \uFFFE, \uFFFF, and special characters
85 * <i>Number:</i>
86 * <i>Integer</i> <i>Exponent<sub>opt</sub></i>
87 * <i>Integer</i> . <i>Fraction</i> <i>Exponent<sub>opt</sub></i>
88 * <i>Integer:</i>
89 * <i>MinimumInteger</i>
90 * #
91 * # <i>Integer</i>
92 * # , <i>Integer</i>
93 * <i>MinimumInteger:</i>
94 * 0
95 * 0 <i>MinimumInteger</i>
96 * 0 , <i>MinimumInteger</i>
97 * <i>Fraction:</i>
98 * <i>MinimumFraction<sub>opt</sub></i> <i>OptionalFraction<sub>opt</sub></i>
99 * <i>MinimumFraction:</i>
100 * 0 <i>MinimumFraction<sub>opt</sub></i>
101 * <i>OptionalFraction:</i>
102 * # <i>OptionalFraction<sub>opt</sub></i>
103 * <i>Exponent:</i>
104 * E <i>MinimumExponent</i>
105 * <i>MinimumExponent:</i>
106 * 0 <i>MinimumExponent<sub>opt</sub></i>
107 * </pre></blockquote>
108 *
109 * <p>A <code>DecimalFormat</code> pattern contains a positive and negative
110 * subpattern, for example, <code>"#,##0.00;(#,##0.00)"</code>. Each
111 * subpattern has a prefix, numeric part, and suffix. The negative subpattern
112 * is optional; if absent, then the positive subpattern prefixed with the
113 * localized minus sign (<code>'-'</code> in most locales) is used as the
114 * negative subpattern. That is, <code>"0.00"</code> alone is equivalent to
115 * <code>"0.00;-0.00"</code>. If there is an explicit negative subpattern, it
116 * serves only to specify the negative prefix and suffix; the number of digits,
117 * minimal digits, and other characteristics are all the same as the positive
118 * pattern. That means that <code>"#,##0.0#;(#)"</code> produces precisely
119 * the same behavior as <code>"#,##0.0#;(#,##0.0#)"</code>.
120 *
121 * <p>The prefixes, suffixes, and various symbols used for infinity, digits,
122 * thousands separators, decimal separators, etc. may be set to arbitrary
123 * values, and they will appear properly during formatting. However, care must
124 * be taken that the symbols and strings do not conflict, or parsing will be
125 * unreliable. For example, either the positive and negative prefixes or the
126 * suffixes must be distinct for <code>DecimalFormat.parse()</code> to be able
127 * to distinguish positive from negative values. (If they are identical, then
128 * <code>DecimalFormat</code> will behave as if no negative subpattern was
129 * specified.) Another example is that the decimal separator and thousands
130 * separator should be distinct characters, or parsing will be impossible.
131 *
132 * <p>The grouping separator is commonly used for thousands, but in some
133 * countries it separates ten-thousands. The grouping size is a constant number
134 * of digits between the grouping characters, such as 3 for 100,000,000 or 4 for
135 * 1,0000,0000. If you supply a pattern with multiple grouping characters, the
136 * interval between the last one and the end of the integer is the one that is
137 * used. So <code>"#,##,###,####"</code> == <code>"######,####"</code> ==
138 * <code>"##,####,####"</code>.
139 *
140 * <h4>Special Pattern Characters</h4>
141 *
142 * <p>Many characters in a pattern are taken literally; they are matched during
143 * parsing and output unchanged during formatting. Special characters, on the
144 * other hand, stand for other characters, strings, or classes of characters.
145 * They must be quoted, unless noted otherwise, if they are to appear in the
146 * prefix or suffix as literals.
147 *
148 * <p>The characters listed here are used in non-localized patterns. Localized
149 * patterns use the corresponding characters taken from this formatter's
150 * <code>DecimalFormatSymbols</code> object instead, and these characters lose
151 * their special status. Two exceptions are the currency sign and quote, which
152 * are not localized.
153 *
154 * <blockquote>
155 * <table class="striped">
156 * <caption style="display:none">Chart showing symbol, location, localized, and meaning.</caption>
157 * <thead>
158 * <tr>
159 * <th style="text-align:left">Symbol
160 * <th style="text-align:left">Location
161 * <th style="text-align:left">Localized?
162 * <th style="text-align:left">Meaning
163 * </thead>
164 * <tbody>
165 * <tr style="vertical-align:top">
166 * <td><code>0</code>
167 * <td>Number
168 * <td>Yes
169 * <td>Digit
170 * <tr style="vertical-align: top">
171 * <td><code>#</code>
172 * <td>Number
173 * <td>Yes
174 * <td>Digit, zero shows as absent
175 * <tr style="vertical-align:top">
176 * <td><code>.</code>
177 * <td>Number
178 * <td>Yes
179 * <td>Decimal separator or monetary decimal separator
180 * <tr style="vertical-align: top">
181 * <td><code>-</code>
182 * <td>Number
183 * <td>Yes
184 * <td>Minus sign
185 * <tr style="vertical-align:top">
186 * <td><code>,</code>
187 * <td>Number
188 * <td>Yes
189 * <td>Grouping separator
190 * <tr style="vertical-align: top">
191 * <td><code>E</code>
192 * <td>Number
193 * <td>Yes
194 * <td>Separates mantissa and exponent in scientific notation.
195 * <em>Need not be quoted in prefix or suffix.</em>
196 * <tr style="vertical-align:top">
197 * <td><code>;</code>
198 * <td>Subpattern boundary
199 * <td>Yes
200 * <td>Separates positive and negative subpatterns
201 * <tr style="vertical-align: top">
202 * <td><code>%</code>
203 * <td>Prefix or suffix
204 * <td>Yes
205 * <td>Multiply by 100 and show as percentage
206 * <tr style="vertical-align:top">
207 * <td><code>\u2030</code>
208 * <td>Prefix or suffix
209 * <td>Yes
210 * <td>Multiply by 1000 and show as per mille value
211 * <tr style="vertical-align: top">
212 * <td><code>¤</code> (<code>\u00A4</code>)
213 * <td>Prefix or suffix
214 * <td>No
215 * <td>Currency sign, replaced by currency symbol. If
216 * doubled, replaced by international currency symbol.
217 * If present in a pattern, the monetary decimal separator
218 * is used instead of the decimal separator.
219 * <tr style="vertical-align:top">
220 * <td><code>'</code>
221 * <td>Prefix or suffix
222 * <td>No
223 * <td>Used to quote special characters in a prefix or suffix,
224 * for example, <code>"'#'#"</code> formats 123 to
225 * <code>"#123"</code>. To create a single quote
226 * itself, use two in a row: <code>"# o''clock"</code>.
227 * </tbody>
228 * </table>
229 * </blockquote>
230 *
231 * <h4>Scientific Notation</h4>
232 *
233 * <p>Numbers in scientific notation are expressed as the product of a mantissa
234 * and a power of ten, for example, 1234 can be expressed as 1.234 x 10^3. The
235 * mantissa is often in the range 1.0 ≤ x {@literal <} 10.0, but it need not
236 * be.
237 * <code>DecimalFormat</code> can be instructed to format and parse scientific
238 * notation <em>only via a pattern</em>; there is currently no factory method
239 * that creates a scientific notation format. In a pattern, the exponent
240 * character immediately followed by one or more digit characters indicates
241 * scientific notation. Example: <code>"0.###E0"</code> formats the number
242 * 1234 as <code>"1.234E3"</code>.
243 *
244 * <ul>
245 * <li>The number of digit characters after the exponent character gives the
246 * minimum exponent digit count. There is no maximum. Negative exponents are
247 * formatted using the localized minus sign, <em>not</em> the prefix and suffix
248 * from the pattern. This allows patterns such as <code>"0.###E0 m/s"</code>.
249 *
250 * <li>The minimum and maximum number of integer digits are interpreted
251 * together:
252 *
253 * <ul>
254 * <li>If the maximum number of integer digits is greater than their minimum number
255 * and greater than 1, it forces the exponent to be a multiple of the maximum
256 * number of integer digits, and the minimum number of integer digits to be
257 * interpreted as 1. The most common use of this is to generate
258 * <em>engineering notation</em>, in which the exponent is a multiple of three,
259 * e.g., <code>"##0.#####E0"</code>. Using this pattern, the number 12345
260 * formats to <code>"12.345E3"</code>, and 123456 formats to
261 * <code>"123.456E3"</code>.
262 *
263 * <li>Otherwise, the minimum number of integer digits is achieved by adjusting the
264 * exponent. Example: 0.00123 formatted with <code>"00.###E0"</code> yields
265 * <code>"12.3E-4"</code>.
266 * </ul>
267 *
268 * <li>The number of significant digits in the mantissa is the sum of the
269 * <em>minimum integer</em> and <em>maximum fraction</em> digits, and is
270 * unaffected by the maximum integer digits. For example, 12345 formatted with
271 * <code>"##0.##E0"</code> is <code>"12.3E3"</code>. To show all digits, set
272 * the significant digits count to zero. The number of significant digits
273 * does not affect parsing.
274 *
275 * <li>Exponential patterns may not contain grouping separators.
276 * </ul>
277 *
278 * <h4>Rounding</h4>
279 *
280 * <code>DecimalFormat</code> provides rounding modes defined in
281 * {@link java.math.RoundingMode} for formatting. By default, it uses
282 * {@link java.math.RoundingMode#HALF_EVEN RoundingMode.HALF_EVEN}.
283 *
284 * <h4>Digits</h4>
285 *
286 * For formatting, <code>DecimalFormat</code> uses the ten consecutive
287 * characters starting with the localized zero digit defined in the
288 * <code>DecimalFormatSymbols</code> object as digits. For parsing, these
289 * digits as well as all Unicode decimal digits, as defined by
290 * {@link Character#digit Character.digit}, are recognized.
291 *
292 * <h4>Special Values</h4>
293 *
294 * <p><code>NaN</code> is formatted as a string, which typically has a single character
295 * <code>\uFFFD</code>. This string is determined by the
296 * <code>DecimalFormatSymbols</code> object. This is the only value for which
297 * the prefixes and suffixes are not used.
298 *
299 * <p>Infinity is formatted as a string, which typically has a single character
300 * <code>\u221E</code>, with the positive or negative prefixes and suffixes
301 * applied. The infinity string is determined by the
302 * <code>DecimalFormatSymbols</code> object.
303 *
304 * <p>Negative zero (<code>"-0"</code>) parses to
305 * <ul>
306 * <li><code>BigDecimal(0)</code> if <code>isParseBigDecimal()</code> is
307 * true,
308 * <li><code>Long(0)</code> if <code>isParseBigDecimal()</code> is false
309 * and <code>isParseIntegerOnly()</code> is true,
310 * <li><code>Double(-0.0)</code> if both <code>isParseBigDecimal()</code>
311 * and <code>isParseIntegerOnly()</code> are false.
312 * </ul>
313 *
314 * <h4><a id="synchronization">Synchronization</a></h4>
315 *
316 * <p>
317 * Decimal formats are generally not synchronized.
318 * It is recommended to create separate format instances for each thread.
319 * If multiple threads access a format concurrently, it must be synchronized
320 * externally.
321 *
322 * <h4>Example</h4>
323 *
324 * <blockquote><pre>{@code
325 * <strong>// Print out a number using the localized number, integer, currency,
326 * // and percent format for each locale</strong>
327 * Locale[] locales = NumberFormat.getAvailableLocales();
328 * double myNumber = -1234.56;
329 * NumberFormat form;
330 * for (int j = 0; j < 4; ++j) {
331 * System.out.println("FORMAT");
332 * for (int i = 0; i < locales.length; ++i) {
333 * if (locales[i].getCountry().length() == 0) {
334 * continue; // Skip language-only locales
335 * }
336 * System.out.print(locales[i].getDisplayName());
337 * switch (j) {
338 * case 0:
339 * form = NumberFormat.getInstance(locales[i]); break;
340 * case 1:
341 * form = NumberFormat.getIntegerInstance(locales[i]); break;
342 * case 2:
343 * form = NumberFormat.getCurrencyInstance(locales[i]); break;
344 * default:
345 * form = NumberFormat.getPercentInstance(locales[i]); break;
346 * }
347 * if (form instanceof DecimalFormat) {
348 * System.out.print(": " + ((DecimalFormat) form).toPattern());
349 * }
350 * System.out.print(" -> " + form.format(myNumber));
351 * try {
352 * System.out.println(" -> " + form.parse(form.format(myNumber)));
353 * } catch (ParseException e) {}
354 * }
355 * }
356 * }</pre></blockquote>
357 *
358 * @see <a href="http://docs.oracle.com/javase/tutorial/i18n/format/decimalFormat.html">Java Tutorial</a>
359 * @see NumberFormat
360 * @see DecimalFormatSymbols
361 * @see ParsePosition
362 * @author Mark Davis
363 * @author Alan Liu
364 * @since 1.1
365 */
366 public class DecimalFormat extends NumberFormat {
367
368 /**
369 * Creates a DecimalFormat using the default pattern and symbols
370 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
371 * This is a convenient way to obtain a
372 * DecimalFormat when internationalization is not the main concern.
373 * <p>
374 * To obtain standard formats for a given locale, use the factory methods
375 * on NumberFormat such as getNumberInstance. These factories will
376 * return the most appropriate sub-class of NumberFormat for a given
377 * locale.
378 *
379 * @see java.text.NumberFormat#getInstance
380 * @see java.text.NumberFormat#getNumberInstance
381 * @see java.text.NumberFormat#getCurrencyInstance
382 * @see java.text.NumberFormat#getPercentInstance
383 */
384 public DecimalFormat() {
385 // Get the pattern for the default locale.
386 Locale def = Locale.getDefault(Locale.Category.FORMAT);
387 LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(NumberFormatProvider.class, def);
388 if (!(adapter instanceof ResourceBundleBasedAdapter)) {
389 adapter = LocaleProviderAdapter.getResourceBundleBased();
390 }
391 String[] all = adapter.getLocaleResources(def).getNumberPatterns();
392
393 // Always applyPattern after the symbols are set
394 this.symbols = DecimalFormatSymbols.getInstance(def);
395 applyPattern(all[0], false);
396 }
397
398
399 /**
400 * Creates a DecimalFormat using the given pattern and the symbols
401 * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
402 * This is a convenient way to obtain a
403 * DecimalFormat when internationalization is not the main concern.
404 * <p>
405 * To obtain standard formats for a given locale, use the factory methods
406 * on NumberFormat such as getNumberInstance. These factories will
407 * return the most appropriate sub-class of NumberFormat for a given
408 * locale.
409 *
410 * @param pattern a non-localized pattern string.
411 * @exception NullPointerException if <code>pattern</code> is null
412 * @exception IllegalArgumentException if the given pattern is invalid.
413 * @see java.text.NumberFormat#getInstance
414 * @see java.text.NumberFormat#getNumberInstance
415 * @see java.text.NumberFormat#getCurrencyInstance
416 * @see java.text.NumberFormat#getPercentInstance
417 */
418 public DecimalFormat(String pattern) {
419 // Always applyPattern after the symbols are set
420 this.symbols = DecimalFormatSymbols.getInstance(Locale.getDefault(Locale.Category.FORMAT));
421 applyPattern(pattern, false);
422 }
423
424
425 /**
426 * Creates a DecimalFormat using the given pattern and symbols.
427 * Use this constructor when you need to completely customize the
428 * behavior of the format.
429 * <p>
430 * To obtain standard formats for a given
431 * locale, use the factory methods on NumberFormat such as
432 * getInstance or getCurrencyInstance. If you need only minor adjustments
433 * to a standard format, you can modify the format returned by
434 * a NumberFormat factory method.
435 *
436 * @param pattern a non-localized pattern string
437 * @param symbols the set of symbols to be used
438 * @exception NullPointerException if any of the given arguments is null
439 * @exception IllegalArgumentException if the given pattern is invalid
440 * @see java.text.NumberFormat#getInstance
441 * @see java.text.NumberFormat#getNumberInstance
442 * @see java.text.NumberFormat#getCurrencyInstance
443 * @see java.text.NumberFormat#getPercentInstance
444 * @see java.text.DecimalFormatSymbols
445 */
446 public DecimalFormat (String pattern, DecimalFormatSymbols symbols) {
447 // Always applyPattern after the symbols are set
448 this.symbols = (DecimalFormatSymbols)symbols.clone();
449 applyPattern(pattern, false);
450 }
451
452
453 // Overrides
454 /**
455 * Formats a number and appends the resulting text to the given string
456 * buffer.
457 * The number can be of any subclass of {@link java.lang.Number}.
458 * <p>
459 * This implementation uses the maximum precision permitted.
460 * @param number the number to format
461 * @param toAppendTo the <code>StringBuffer</code> to which the formatted
462 * text is to be appended
463 * @param pos On input: an alignment field, if desired.
464 * On output: the offsets of the alignment field.
465 * @return the value passed in as <code>toAppendTo</code>
466 * @exception IllegalArgumentException if <code>number</code> is
467 * null or not an instance of <code>Number</code>.
468 * @exception NullPointerException if <code>toAppendTo</code> or
469 * <code>pos</code> is null
470 * @exception ArithmeticException if rounding is needed with rounding
471 * mode being set to RoundingMode.UNNECESSARY
472 * @see java.text.FieldPosition
473 */
474 @Override
475 public final StringBuffer format(Object number,
476 StringBuffer toAppendTo,
477 FieldPosition pos) {
478 if (number instanceof Long || number instanceof Integer ||
479 number instanceof Short || number instanceof Byte ||
480 number instanceof AtomicInteger ||
481 number instanceof AtomicLong ||
482 (number instanceof BigInteger &&
483 ((BigInteger)number).bitLength () < 64)) {
484 return format(((Number)number).longValue(), toAppendTo, pos);
485 } else if (number instanceof BigDecimal) {
486 return format((BigDecimal)number, toAppendTo, pos);
487 } else if (number instanceof BigInteger) {
488 return format((BigInteger)number, toAppendTo, pos);
489 } else if (number instanceof Number) {
490 return format(((Number)number).doubleValue(), toAppendTo, pos);
491 } else {
492 throw new IllegalArgumentException("Cannot format given Object as a Number");
493 }
494 }
495
496 /**
497 * Formats a double to produce a string.
498 * @param number The double to format
499 * @param result where the text is to be appended
500 * @param fieldPosition On input: an alignment field, if desired.
501 * On output: the offsets of the alignment field.
502 * @exception NullPointerException if {@code result} or
503 * {@code fieldPosition} is {@code null}
504 * @exception ArithmeticException if rounding is needed with rounding
505 * mode being set to RoundingMode.UNNECESSARY
506 * @return The formatted number string
507 * @see java.text.FieldPosition
508 */
509 @Override
510 public StringBuffer format(double number, StringBuffer result,
511 FieldPosition fieldPosition) {
512 // If fieldPosition is a DontCareFieldPosition instance we can
513 // try to go to fast-path code.
514 boolean tryFastPath = false;
515 if (fieldPosition == DontCareFieldPosition.INSTANCE)
516 tryFastPath = true;
517 else {
518 fieldPosition.setBeginIndex(0);
519 fieldPosition.setEndIndex(0);
520 }
521
522 if (tryFastPath) {
523 String tempResult = fastFormat(number);
524 if (tempResult != null) {
525 result.append(tempResult);
526 return result;
527 }
528 }
529
530 // if fast-path could not work, we fallback to standard code.
531 return format(number, result, fieldPosition.getFieldDelegate());
532 }
533
534 /**
535 * Formats a double to produce a string.
536 * @param number The double to format
537 * @param result where the text is to be appended
538 * @param delegate notified of locations of sub fields
539 * @exception ArithmeticException if rounding is needed with rounding
540 * mode being set to RoundingMode.UNNECESSARY
541 * @return The formatted number string
542 */
543 private StringBuffer format(double number, StringBuffer result,
544 FieldDelegate delegate) {
545 if (Double.isNaN(number) ||
546 (Double.isInfinite(number) && multiplier == 0)) {
547 int iFieldStart = result.length();
548 result.append(symbols.getNaN());
549 delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
550 iFieldStart, result.length(), result);
551 return result;
552 }
553
554 /* Detecting whether a double is negative is easy with the exception of
555 * the value -0.0. This is a double which has a zero mantissa (and
556 * exponent), but a negative sign bit. It is semantically distinct from
557 * a zero with a positive sign bit, and this distinction is important
558 * to certain kinds of computations. However, it's a little tricky to
559 * detect, since (-0.0 == 0.0) and !(-0.0 < 0.0). How then, you may
560 * ask, does it behave distinctly from +0.0? Well, 1/(-0.0) ==
561 * -Infinity. Proper detection of -0.0 is needed to deal with the
562 * issues raised by bugs 4106658, 4106667, and 4147706. Liu 7/6/98.
563 */
564 boolean isNegative = ((number < 0.0) || (number == 0.0 && 1/number < 0.0)) ^ (multiplier < 0);
565
566 if (multiplier != 1) {
567 number *= multiplier;
568 }
569
570 if (Double.isInfinite(number)) {
571 if (isNegative) {
572 append(result, negativePrefix, delegate,
573 getNegativePrefixFieldPositions(), Field.SIGN);
574 } else {
575 append(result, positivePrefix, delegate,
576 getPositivePrefixFieldPositions(), Field.SIGN);
577 }
578
579 int iFieldStart = result.length();
580 result.append(symbols.getInfinity());
581 delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
582 iFieldStart, result.length(), result);
583
584 if (isNegative) {
585 append(result, negativeSuffix, delegate,
586 getNegativeSuffixFieldPositions(), Field.SIGN);
587 } else {
588 append(result, positiveSuffix, delegate,
589 getPositiveSuffixFieldPositions(), Field.SIGN);
590 }
591
592 return result;
593 }
594
595 if (isNegative) {
596 number = -number;
597 }
598
599 // at this point we are guaranteed a nonnegative finite number.
600 assert(number >= 0 && !Double.isInfinite(number));
601
602 synchronized(digitList) {
603 int maxIntDigits = super.getMaximumIntegerDigits();
604 int minIntDigits = super.getMinimumIntegerDigits();
605 int maxFraDigits = super.getMaximumFractionDigits();
606 int minFraDigits = super.getMinimumFractionDigits();
607
608 digitList.set(isNegative, number, useExponentialNotation ?
609 maxIntDigits + maxFraDigits : maxFraDigits,
610 !useExponentialNotation);
611 return subformat(result, delegate, isNegative, false,
612 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
613 }
614 }
615
616 /**
617 * Format a long to produce a string.
618 * @param number The long to format
619 * @param result where the text is to be appended
620 * @param fieldPosition On input: an alignment field, if desired.
621 * On output: the offsets of the alignment field.
622 * @exception NullPointerException if {@code result} or
623 * {@code fieldPosition} is {@code null}
624 * @exception ArithmeticException if rounding is needed with rounding
625 * mode being set to RoundingMode.UNNECESSARY
626 * @return The formatted number string
627 * @see java.text.FieldPosition
628 */
629 @Override
630 public StringBuffer format(long number, StringBuffer result,
631 FieldPosition fieldPosition) {
632 fieldPosition.setBeginIndex(0);
633 fieldPosition.setEndIndex(0);
634
635 return format(number, result, fieldPosition.getFieldDelegate());
636 }
637
638 /**
639 * Format a long to produce a string.
640 * @param number The long to format
641 * @param result where the text is to be appended
642 * @param delegate notified of locations of sub fields
643 * @return The formatted number string
644 * @exception ArithmeticException if rounding is needed with rounding
645 * mode being set to RoundingMode.UNNECESSARY
646 * @see java.text.FieldPosition
647 */
648 private StringBuffer format(long number, StringBuffer result,
649 FieldDelegate delegate) {
650 boolean isNegative = (number < 0);
651 if (isNegative) {
652 number = -number;
653 }
654
655 // In general, long values always represent real finite numbers, so
656 // we don't have to check for +/- Infinity or NaN. However, there
657 // is one case we have to be careful of: The multiplier can push
658 // a number near MIN_VALUE or MAX_VALUE outside the legal range. We
659 // check for this before multiplying, and if it happens we use
660 // BigInteger instead.
661 boolean useBigInteger = false;
662 if (number < 0) { // This can only happen if number == Long.MIN_VALUE.
663 if (multiplier != 0) {
664 useBigInteger = true;
665 }
666 } else if (multiplier != 1 && multiplier != 0) {
667 long cutoff = Long.MAX_VALUE / multiplier;
668 if (cutoff < 0) {
669 cutoff = -cutoff;
670 }
671 useBigInteger = (number > cutoff);
672 }
673
674 if (useBigInteger) {
675 if (isNegative) {
676 number = -number;
677 }
678 BigInteger bigIntegerValue = BigInteger.valueOf(number);
679 return format(bigIntegerValue, result, delegate, true);
680 }
681
682 number *= multiplier;
683 if (number == 0) {
684 isNegative = false;
685 } else {
686 if (multiplier < 0) {
687 number = -number;
688 isNegative = !isNegative;
689 }
690 }
691
692 synchronized(digitList) {
693 int maxIntDigits = super.getMaximumIntegerDigits();
694 int minIntDigits = super.getMinimumIntegerDigits();
695 int maxFraDigits = super.getMaximumFractionDigits();
696 int minFraDigits = super.getMinimumFractionDigits();
697
698 digitList.set(isNegative, number,
699 useExponentialNotation ? maxIntDigits + maxFraDigits : 0);
700
701 return subformat(result, delegate, isNegative, true,
702 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
703 }
704 }
705
706 /**
707 * Formats a BigDecimal to produce a string.
708 * @param number The BigDecimal to format
709 * @param result where the text is to be appended
710 * @param fieldPosition On input: an alignment field, if desired.
711 * On output: the offsets of the alignment field.
712 * @return The formatted number string
713 * @exception ArithmeticException if rounding is needed with rounding
714 * mode being set to RoundingMode.UNNECESSARY
715 * @see java.text.FieldPosition
716 */
717 private StringBuffer format(BigDecimal number, StringBuffer result,
718 FieldPosition fieldPosition) {
719 fieldPosition.setBeginIndex(0);
720 fieldPosition.setEndIndex(0);
721 return format(number, result, fieldPosition.getFieldDelegate());
722 }
723
724 /**
725 * Formats a BigDecimal to produce a string.
726 * @param number The BigDecimal to format
727 * @param result where the text is to be appended
728 * @param delegate notified of locations of sub fields
729 * @exception ArithmeticException if rounding is needed with rounding
730 * mode being set to RoundingMode.UNNECESSARY
731 * @return The formatted number string
732 */
733 private StringBuffer format(BigDecimal number, StringBuffer result,
734 FieldDelegate delegate) {
735 if (multiplier != 1) {
736 number = number.multiply(getBigDecimalMultiplier());
737 }
738 boolean isNegative = number.signum() == -1;
739 if (isNegative) {
740 number = number.negate();
741 }
742
743 synchronized(digitList) {
744 int maxIntDigits = getMaximumIntegerDigits();
745 int minIntDigits = getMinimumIntegerDigits();
746 int maxFraDigits = getMaximumFractionDigits();
747 int minFraDigits = getMinimumFractionDigits();
748 int maximumDigits = maxIntDigits + maxFraDigits;
749
750 digitList.set(isNegative, number, useExponentialNotation ?
751 ((maximumDigits < 0) ? Integer.MAX_VALUE : maximumDigits) :
752 maxFraDigits, !useExponentialNotation);
753
754 return subformat(result, delegate, isNegative, false,
755 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
756 }
757 }
758
759 /**
760 * Format a BigInteger to produce a string.
761 * @param number The BigInteger to format
762 * @param result where the text is to be appended
763 * @param fieldPosition On input: an alignment field, if desired.
764 * On output: the offsets of the alignment field.
765 * @return The formatted number string
766 * @exception ArithmeticException if rounding is needed with rounding
767 * mode being set to RoundingMode.UNNECESSARY
768 * @see java.text.FieldPosition
769 */
770 private StringBuffer format(BigInteger number, StringBuffer result,
771 FieldPosition fieldPosition) {
772 fieldPosition.setBeginIndex(0);
773 fieldPosition.setEndIndex(0);
774
775 return format(number, result, fieldPosition.getFieldDelegate(), false);
776 }
777
778 /**
779 * Format a BigInteger to produce a string.
780 * @param number The BigInteger to format
781 * @param result where the text is to be appended
782 * @param delegate notified of locations of sub fields
783 * @return The formatted number string
784 * @exception ArithmeticException if rounding is needed with rounding
785 * mode being set to RoundingMode.UNNECESSARY
786 * @see java.text.FieldPosition
787 */
788 private StringBuffer format(BigInteger number, StringBuffer result,
789 FieldDelegate delegate, boolean formatLong) {
790 if (multiplier != 1) {
791 number = number.multiply(getBigIntegerMultiplier());
792 }
793 boolean isNegative = number.signum() == -1;
794 if (isNegative) {
795 number = number.negate();
796 }
797
798 synchronized(digitList) {
799 int maxIntDigits, minIntDigits, maxFraDigits, minFraDigits, maximumDigits;
800 if (formatLong) {
801 maxIntDigits = super.getMaximumIntegerDigits();
802 minIntDigits = super.getMinimumIntegerDigits();
803 maxFraDigits = super.getMaximumFractionDigits();
804 minFraDigits = super.getMinimumFractionDigits();
805 maximumDigits = maxIntDigits + maxFraDigits;
806 } else {
807 maxIntDigits = getMaximumIntegerDigits();
808 minIntDigits = getMinimumIntegerDigits();
809 maxFraDigits = getMaximumFractionDigits();
810 minFraDigits = getMinimumFractionDigits();
811 maximumDigits = maxIntDigits + maxFraDigits;
812 if (maximumDigits < 0) {
813 maximumDigits = Integer.MAX_VALUE;
814 }
815 }
816
817 digitList.set(isNegative, number,
818 useExponentialNotation ? maximumDigits : 0);
819
820 return subformat(result, delegate, isNegative, true,
821 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
822 }
823 }
824
825 /**
826 * Formats an Object producing an <code>AttributedCharacterIterator</code>.
827 * You can use the returned <code>AttributedCharacterIterator</code>
828 * to build the resulting String, as well as to determine information
829 * about the resulting String.
830 * <p>
831 * Each attribute key of the AttributedCharacterIterator will be of type
832 * <code>NumberFormat.Field</code>, with the attribute value being the
833 * same as the attribute key.
834 *
835 * @exception NullPointerException if obj is null.
836 * @exception IllegalArgumentException when the Format cannot format the
837 * given object.
838 * @exception ArithmeticException if rounding is needed with rounding
839 * mode being set to RoundingMode.UNNECESSARY
840 * @param obj The object to format
841 * @return AttributedCharacterIterator describing the formatted value.
842 * @since 1.4
843 */
844 @Override
845 public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
846 CharacterIteratorFieldDelegate delegate =
847 new CharacterIteratorFieldDelegate();
848 StringBuffer sb = new StringBuffer();
849
850 if (obj instanceof Double || obj instanceof Float) {
851 format(((Number)obj).doubleValue(), sb, delegate);
852 } else if (obj instanceof Long || obj instanceof Integer ||
853 obj instanceof Short || obj instanceof Byte ||
854 obj instanceof AtomicInteger || obj instanceof AtomicLong) {
855 format(((Number)obj).longValue(), sb, delegate);
856 } else if (obj instanceof BigDecimal) {
857 format((BigDecimal)obj, sb, delegate);
858 } else if (obj instanceof BigInteger) {
859 format((BigInteger)obj, sb, delegate, false);
860 } else if (obj == null) {
861 throw new NullPointerException(
862 "formatToCharacterIterator must be passed non-null object");
863 } else {
864 throw new IllegalArgumentException(
865 "Cannot format given Object as a Number");
866 }
867 return delegate.getIterator(sb.toString());
868 }
869
870 // ==== Begin fast-path formating logic for double =========================
871
872 /* Fast-path formatting will be used for format(double ...) methods iff a
873 * number of conditions are met (see checkAndSetFastPathStatus()):
874 * - Only if instance properties meet the right predefined conditions.
875 * - The abs value of the double to format is <= Integer.MAX_VALUE.
876 *
877 * The basic approach is to split the binary to decimal conversion of a
878 * double value into two phases:
879 * * The conversion of the integer portion of the double.
880 * * The conversion of the fractional portion of the double
881 * (limited to two or three digits).
882 *
883 * The isolation and conversion of the integer portion of the double is
884 * straightforward. The conversion of the fraction is more subtle and relies
885 * on some rounding properties of double to the decimal precisions in
886 * question. Using the terminology of BigDecimal, this fast-path algorithm
887 * is applied when a double value has a magnitude less than Integer.MAX_VALUE
888 * and rounding is to nearest even and the destination format has two or
889 * three digits of *scale* (digits after the decimal point).
890 *
891 * Under a rounding to nearest even policy, the returned result is a digit
892 * string of a number in the (in this case decimal) destination format
893 * closest to the exact numerical value of the (in this case binary) input
894 * value. If two destination format numbers are equally distant, the one
895 * with the last digit even is returned. To compute such a correctly rounded
896 * value, some information about digits beyond the smallest returned digit
897 * position needs to be consulted.
898 *
899 * In general, a guard digit, a round digit, and a sticky *bit* are needed
900 * beyond the returned digit position. If the discarded portion of the input
901 * is sufficiently large, the returned digit string is incremented. In round
902 * to nearest even, this threshold to increment occurs near the half-way
903 * point between digits. The sticky bit records if there are any remaining
904 * trailing digits of the exact input value in the new format; the sticky bit
905 * is consulted only in close to half-way rounding cases.
906 *
907 * Given the computation of the digit and bit values, rounding is then
908 * reduced to a table lookup problem. For decimal, the even/odd cases look
909 * like this:
910 *
911 * Last Round Sticky
912 * 6 5 0 => 6 // exactly halfway, return even digit.
913 * 6 5 1 => 7 // a little bit more than halfway, round up.
914 * 7 5 0 => 8 // exactly halfway, round up to even.
915 * 7 5 1 => 8 // a little bit more than halfway, round up.
916 * With analogous entries for other even and odd last-returned digits.
917 *
918 * However, decimal negative powers of 5 smaller than 0.5 are *not* exactly
919 * representable as binary fraction. In particular, 0.005 (the round limit
920 * for a two-digit scale) and 0.0005 (the round limit for a three-digit
921 * scale) are not representable. Therefore, for input values near these cases
922 * the sticky bit is known to be set which reduces the rounding logic to:
923 *
924 * Last Round Sticky
925 * 6 5 1 => 7 // a little bit more than halfway, round up.
926 * 7 5 1 => 8 // a little bit more than halfway, round up.
927 *
928 * In other words, if the round digit is 5, the sticky bit is known to be
929 * set. If the round digit is something other than 5, the sticky bit is not
930 * relevant. Therefore, some of the logic about whether or not to increment
931 * the destination *decimal* value can occur based on tests of *binary*
932 * computations of the binary input number.
933 */
934
935 /**
936 * Check validity of using fast-path for this instance. If fast-path is valid
937 * for this instance, sets fast-path state as true and initializes fast-path
938 * utility fields as needed.
939 *
940 * This method is supposed to be called rarely, otherwise that will break the
941 * fast-path performance. That means avoiding frequent changes of the
942 * properties of the instance, since for most properties, each time a change
943 * happens, a call to this method is needed at the next format call.
944 *
945 * FAST-PATH RULES:
946 * Similar to the default DecimalFormat instantiation case.
947 * More precisely:
948 * - HALF_EVEN rounding mode,
949 * - isGroupingUsed() is true,
950 * - groupingSize of 3,
951 * - multiplier is 1,
952 * - Decimal separator not mandatory,
953 * - No use of exponential notation,
954 * - minimumIntegerDigits is exactly 1 and maximumIntegerDigits at least 10
955 * - For number of fractional digits, the exact values found in the default case:
956 * Currency : min = max = 2.
957 * Decimal : min = 0. max = 3.
958 *
959 */
960 private boolean checkAndSetFastPathStatus() {
961
962 boolean fastPathWasOn = isFastPath;
963
964 if ((roundingMode == RoundingMode.HALF_EVEN) &&
965 (isGroupingUsed()) &&
966 (groupingSize == 3) &&
967 (multiplier == 1) &&
968 (!decimalSeparatorAlwaysShown) &&
969 (!useExponentialNotation)) {
970
971 // The fast-path algorithm is semi-hardcoded against
972 // minimumIntegerDigits and maximumIntegerDigits.
973 isFastPath = ((minimumIntegerDigits == 1) &&
974 (maximumIntegerDigits >= 10));
975
976 // The fast-path algorithm is hardcoded against
977 // minimumFractionDigits and maximumFractionDigits.
978 if (isFastPath) {
979 if (isCurrencyFormat) {
980 if ((minimumFractionDigits != 2) ||
981 (maximumFractionDigits != 2))
982 isFastPath = false;
983 } else if ((minimumFractionDigits != 0) ||
984 (maximumFractionDigits != 3))
985 isFastPath = false;
986 }
987 } else
988 isFastPath = false;
989
990 resetFastPathData(fastPathWasOn);
991 fastPathCheckNeeded = false;
992
993 /*
994 * Returns true after successfully checking the fast path condition and
995 * setting the fast path data. The return value is used by the
996 * fastFormat() method to decide whether to call the resetFastPathData
997 * method to reinitialize fast path data or is it already initialized
998 * in this method.
999 */
1000 return true;
1001 }
1002
1003 private void resetFastPathData(boolean fastPathWasOn) {
1004 // Since some instance properties may have changed while still falling
1005 // in the fast-path case, we need to reinitialize fastPathData anyway.
1006 if (isFastPath) {
1007 // We need to instantiate fastPathData if not already done.
1008 if (fastPathData == null) {
1009 fastPathData = new FastPathData();
1010 }
1011
1012 // Sets up the locale specific constants used when formatting.
1013 // '0' is our default representation of zero.
1014 fastPathData.zeroDelta = symbols.getZeroDigit() - '0';
1015 fastPathData.groupingChar = symbols.getGroupingSeparator();
1016
1017 // Sets up fractional constants related to currency/decimal pattern.
1018 fastPathData.fractionalMaxIntBound = (isCurrencyFormat)
1019 ? 99 : 999;
1020 fastPathData.fractionalScaleFactor = (isCurrencyFormat)
1021 ? 100.0d : 1000.0d;
1022
1023 // Records the need for adding prefix or suffix
1024 fastPathData.positiveAffixesRequired
1025 = (positivePrefix.length() != 0)
1026 || (positiveSuffix.length() != 0);
1027 fastPathData.negativeAffixesRequired
1028 = (negativePrefix.length() != 0)
1029 || (negativeSuffix.length() != 0);
1030
1031 // Creates a cached char container for result, with max possible size.
1032 int maxNbIntegralDigits = 10;
1033 int maxNbGroups = 3;
1034 int containerSize
1035 = Math.max(positivePrefix.length(), negativePrefix.length())
1036 + maxNbIntegralDigits + maxNbGroups + 1
1037 + maximumFractionDigits
1038 + Math.max(positiveSuffix.length(), negativeSuffix.length());
1039
1040 fastPathData.fastPathContainer = new char[containerSize];
1041
1042 // Sets up prefix and suffix char arrays constants.
1043 fastPathData.charsPositiveSuffix = positiveSuffix.toCharArray();
1044 fastPathData.charsNegativeSuffix = negativeSuffix.toCharArray();
1045 fastPathData.charsPositivePrefix = positivePrefix.toCharArray();
1046 fastPathData.charsNegativePrefix = negativePrefix.toCharArray();
1047
1048 // Sets up fixed index positions for integral and fractional digits.
1049 // Sets up decimal point in cached result container.
1050 int longestPrefixLength
1051 = Math.max(positivePrefix.length(),
1052 negativePrefix.length());
1053 int decimalPointIndex
1054 = maxNbIntegralDigits + maxNbGroups + longestPrefixLength;
1055
1056 fastPathData.integralLastIndex = decimalPointIndex - 1;
1057 fastPathData.fractionalFirstIndex = decimalPointIndex + 1;
1058 fastPathData.fastPathContainer[decimalPointIndex]
1059 = isCurrencyFormat
1060 ? symbols.getMonetaryDecimalSeparator()
1061 : symbols.getDecimalSeparator();
1062
1063 } else if (fastPathWasOn) {
1064 // Previous state was fast-path and is no more.
1065 // Resets cached array constants.
1066 fastPathData.fastPathContainer = null;
1067 fastPathData.charsPositiveSuffix = null;
1068 fastPathData.charsNegativeSuffix = null;
1069 fastPathData.charsPositivePrefix = null;
1070 fastPathData.charsNegativePrefix = null;
1071 }
1072 }
1073
1074 /**
1075 * Returns true if rounding-up must be done on {@code scaledFractionalPartAsInt},
1076 * false otherwise.
1077 *
1078 * This is a utility method that takes correct half-even rounding decision on
1079 * passed fractional value at the scaled decimal point (2 digits for currency
1080 * case and 3 for decimal case), when the approximated fractional part after
1081 * scaled decimal point is exactly 0.5d. This is done by means of exact
1082 * calculations on the {@code fractionalPart} floating-point value.
1083 *
1084 * This method is supposed to be called by private {@code fastDoubleFormat}
1085 * method only.
1086 *
1087 * The algorithms used for the exact calculations are :
1088 *
1089 * The <b><i>FastTwoSum</i></b> algorithm, from T.J.Dekker, described in the
1090 * papers "<i>A Floating-Point Technique for Extending the Available
1091 * Precision</i>" by Dekker, and in "<i>Adaptive Precision Floating-Point
1092 * Arithmetic and Fast Robust Geometric Predicates</i>" from J.Shewchuk.
1093 *
1094 * A modified version of <b><i>Sum2S</i></b> cascaded summation described in
1095 * "<i>Accurate Sum and Dot Product</i>" from Takeshi Ogita and All. As
1096 * Ogita says in this paper this is an equivalent of the Kahan-Babuska's
1097 * summation algorithm because we order the terms by magnitude before summing
1098 * them. For this reason we can use the <i>FastTwoSum</i> algorithm rather
1099 * than the more expensive Knuth's <i>TwoSum</i>.
1100 *
1101 * We do this to avoid a more expensive exact "<i>TwoProduct</i>" algorithm,
1102 * like those described in Shewchuk's paper above. See comments in the code
1103 * below.
1104 *
1105 * @param fractionalPart The fractional value on which we take rounding
1106 * decision.
1107 * @param scaledFractionalPartAsInt The integral part of the scaled
1108 * fractional value.
1109 *
1110 * @return the decision that must be taken regarding half-even rounding.
1111 */
1112 private boolean exactRoundUp(double fractionalPart,
1113 int scaledFractionalPartAsInt) {
1114
1115 /* exactRoundUp() method is called by fastDoubleFormat() only.
1116 * The precondition expected to be verified by the passed parameters is :
1117 * scaledFractionalPartAsInt ==
1118 * (int) (fractionalPart * fastPathData.fractionalScaleFactor).
1119 * This is ensured by fastDoubleFormat() code.
1120 */
1121
1122 /* We first calculate roundoff error made by fastDoubleFormat() on
1123 * the scaled fractional part. We do this with exact calculation on the
1124 * passed fractionalPart. Rounding decision will then be taken from roundoff.
1125 */
1126
1127 /* ---- TwoProduct(fractionalPart, scale factor (i.e. 1000.0d or 100.0d)).
1128 *
1129 * The below is an optimized exact "TwoProduct" calculation of passed
1130 * fractional part with scale factor, using Ogita's Sum2S cascaded
1131 * summation adapted as Kahan-Babuska equivalent by using FastTwoSum
1132 * (much faster) rather than Knuth's TwoSum.
1133 *
1134 * We can do this because we order the summation from smallest to
1135 * greatest, so that FastTwoSum can be used without any additional error.
1136 *
1137 * The "TwoProduct" exact calculation needs 17 flops. We replace this by
1138 * a cascaded summation of FastTwoSum calculations, each involving an
1139 * exact multiply by a power of 2.
1140 *
1141 * Doing so saves overall 4 multiplications and 1 addition compared to
1142 * using traditional "TwoProduct".
1143 *
1144 * The scale factor is either 100 (currency case) or 1000 (decimal case).
1145 * - when 1000, we replace it by (1024 - 16 - 8) = 1000.
1146 * - when 100, we replace it by (128 - 32 + 4) = 100.
1147 * Every multiplication by a power of 2 (1024, 128, 32, 16, 8, 4) is exact.
1148 *
1149 */
1150 double approxMax; // Will always be positive.
1151 double approxMedium; // Will always be negative.
1152 double approxMin;
1153
1154 double fastTwoSumApproximation = 0.0d;
1155 double fastTwoSumRoundOff = 0.0d;
1156 double bVirtual = 0.0d;
1157
1158 if (isCurrencyFormat) {
1159 // Scale is 100 = 128 - 32 + 4.
1160 // Multiply by 2**n is a shift. No roundoff. No error.
1161 approxMax = fractionalPart * 128.00d;
1162 approxMedium = - (fractionalPart * 32.00d);
1163 approxMin = fractionalPart * 4.00d;
1164 } else {
1165 // Scale is 1000 = 1024 - 16 - 8.
1166 // Multiply by 2**n is a shift. No roundoff. No error.
1167 approxMax = fractionalPart * 1024.00d;
1168 approxMedium = - (fractionalPart * 16.00d);
1169 approxMin = - (fractionalPart * 8.00d);
1170 }
1171
1172 // Shewchuk/Dekker's FastTwoSum(approxMedium, approxMin).
1173 assert(-approxMedium >= Math.abs(approxMin));
1174 fastTwoSumApproximation = approxMedium + approxMin;
1175 bVirtual = fastTwoSumApproximation - approxMedium;
1176 fastTwoSumRoundOff = approxMin - bVirtual;
1177 double approxS1 = fastTwoSumApproximation;
1178 double roundoffS1 = fastTwoSumRoundOff;
1179
1180 // Shewchuk/Dekker's FastTwoSum(approxMax, approxS1);
1181 assert(approxMax >= Math.abs(approxS1));
1182 fastTwoSumApproximation = approxMax + approxS1;
1183 bVirtual = fastTwoSumApproximation - approxMax;
1184 fastTwoSumRoundOff = approxS1 - bVirtual;
1185 double roundoff1000 = fastTwoSumRoundOff;
1186 double approx1000 = fastTwoSumApproximation;
1187 double roundoffTotal = roundoffS1 + roundoff1000;
1188
1189 // Shewchuk/Dekker's FastTwoSum(approx1000, roundoffTotal);
1190 assert(approx1000 >= Math.abs(roundoffTotal));
1191 fastTwoSumApproximation = approx1000 + roundoffTotal;
1192 bVirtual = fastTwoSumApproximation - approx1000;
1193
1194 // Now we have got the roundoff for the scaled fractional
1195 double scaledFractionalRoundoff = roundoffTotal - bVirtual;
1196
1197 // ---- TwoProduct(fractionalPart, scale (i.e. 1000.0d or 100.0d)) end.
1198
1199 /* ---- Taking the rounding decision
1200 *
1201 * We take rounding decision based on roundoff and half-even rounding
1202 * rule.
1203 *
1204 * The above TwoProduct gives us the exact roundoff on the approximated
1205 * scaled fractional, and we know that this approximation is exactly
1206 * 0.5d, since that has already been tested by the caller
1207 * (fastDoubleFormat).
1208 *
1209 * Decision comes first from the sign of the calculated exact roundoff.
1210 * - Since being exact roundoff, it cannot be positive with a scaled
1211 * fractional less than 0.5d, as well as negative with a scaled
1212 * fractional greater than 0.5d. That leaves us with following 3 cases.
1213 * - positive, thus scaled fractional == 0.500....0fff ==> round-up.
1214 * - negative, thus scaled fractional == 0.499....9fff ==> don't round-up.
1215 * - is zero, thus scaled fractioanl == 0.5 ==> half-even rounding applies :
1216 * we round-up only if the integral part of the scaled fractional is odd.
1217 *
1218 */
1219 if (scaledFractionalRoundoff > 0.0) {
1220 return true;
1221 } else if (scaledFractionalRoundoff < 0.0) {
1222 return false;
1223 } else if ((scaledFractionalPartAsInt & 1) != 0) {
1224 return true;
1225 }
1226
1227 return false;
1228
1229 // ---- Taking the rounding decision end
1230 }
1231
1232 /**
1233 * Collects integral digits from passed {@code number}, while setting
1234 * grouping chars as needed. Updates {@code firstUsedIndex} accordingly.
1235 *
1236 * Loops downward starting from {@code backwardIndex} position (inclusive).
1237 *
1238 * @param number The int value from which we collect digits.
1239 * @param digitsBuffer The char array container where digits and grouping chars
1240 * are stored.
1241 * @param backwardIndex the position from which we start storing digits in
1242 * digitsBuffer.
1243 *
1244 */
1245 private void collectIntegralDigits(int number,
1246 char[] digitsBuffer,
1247 int backwardIndex) {
1248 int index = backwardIndex;
1249 int q;
1250 int r;
1251 while (number > 999) {
1252 // Generates 3 digits per iteration.
1253 q = number / 1000;
1254 r = number - (q << 10) + (q << 4) + (q << 3); // -1024 +16 +8 = 1000.
1255 number = q;
1256
1257 digitsBuffer[index--] = DigitArrays.DigitOnes1000[r];
1258 digitsBuffer[index--] = DigitArrays.DigitTens1000[r];
1259 digitsBuffer[index--] = DigitArrays.DigitHundreds1000[r];
1260 digitsBuffer[index--] = fastPathData.groupingChar;
1261 }
1262
1263 // Collects last 3 or less digits.
1264 digitsBuffer[index] = DigitArrays.DigitOnes1000[number];
1265 if (number > 9) {
1266 digitsBuffer[--index] = DigitArrays.DigitTens1000[number];
1267 if (number > 99)
1268 digitsBuffer[--index] = DigitArrays.DigitHundreds1000[number];
1269 }
1270
1271 fastPathData.firstUsedIndex = index;
1272 }
1273
1274 /**
1275 * Collects the 2 (currency) or 3 (decimal) fractional digits from passed
1276 * {@code number}, starting at {@code startIndex} position
1277 * inclusive. There is no punctuation to set here (no grouping chars).
1278 * Updates {@code fastPathData.lastFreeIndex} accordingly.
1279 *
1280 *
1281 * @param number The int value from which we collect digits.
1282 * @param digitsBuffer The char array container where digits are stored.
1283 * @param startIndex the position from which we start storing digits in
1284 * digitsBuffer.
1285 *
1286 */
1287 private void collectFractionalDigits(int number,
1288 char[] digitsBuffer,
1289 int startIndex) {
1290 int index = startIndex;
1291
1292 char digitOnes = DigitArrays.DigitOnes1000[number];
1293 char digitTens = DigitArrays.DigitTens1000[number];
1294
1295 if (isCurrencyFormat) {
1296 // Currency case. Always collects fractional digits.
1297 digitsBuffer[index++] = digitTens;
1298 digitsBuffer[index++] = digitOnes;
1299 } else if (number != 0) {
1300 // Decimal case. Hundreds will always be collected
1301 digitsBuffer[index++] = DigitArrays.DigitHundreds1000[number];
1302
1303 // Ending zeros won't be collected.
1304 if (digitOnes != '0') {
1305 digitsBuffer[index++] = digitTens;
1306 digitsBuffer[index++] = digitOnes;
1307 } else if (digitTens != '0')
1308 digitsBuffer[index++] = digitTens;
1309
1310 } else
1311 // This is decimal pattern and fractional part is zero.
1312 // We must remove decimal point from result.
1313 index--;
1314
1315 fastPathData.lastFreeIndex = index;
1316 }
1317
1318 /**
1319 * Internal utility.
1320 * Adds the passed {@code prefix} and {@code suffix} to {@code container}.
1321 *
1322 * @param container Char array container which to prepend/append the
1323 * prefix/suffix.
1324 * @param prefix Char sequence to prepend as a prefix.
1325 * @param suffix Char sequence to append as a suffix.
1326 *
1327 */
1328 // private void addAffixes(boolean isNegative, char[] container) {
1329 private void addAffixes(char[] container, char[] prefix, char[] suffix) {
1330
1331 // We add affixes only if needed (affix length > 0).
1332 int pl = prefix.length;
1333 int sl = suffix.length;
1334 if (pl != 0) prependPrefix(prefix, pl, container);
1335 if (sl != 0) appendSuffix(suffix, sl, container);
1336
1337 }
1338
1339 /**
1340 * Prepends the passed {@code prefix} chars to given result
1341 * {@code container}. Updates {@code fastPathData.firstUsedIndex}
1342 * accordingly.
1343 *
1344 * @param prefix The prefix characters to prepend to result.
1345 * @param len The number of chars to prepend.
1346 * @param container Char array container which to prepend the prefix
1347 */
1348 private void prependPrefix(char[] prefix,
1349 int len,
1350 char[] container) {
1351
1352 fastPathData.firstUsedIndex -= len;
1353 int startIndex = fastPathData.firstUsedIndex;
1354
1355 // If prefix to prepend is only 1 char long, just assigns this char.
1356 // If prefix is less or equal 4, we use a dedicated algorithm that
1357 // has shown to run faster than System.arraycopy.
1358 // If more than 4, we use System.arraycopy.
1359 if (len == 1)
1360 container[startIndex] = prefix[0];
1361 else if (len <= 4) {
1362 int dstLower = startIndex;
1363 int dstUpper = dstLower + len - 1;
1364 int srcUpper = len - 1;
1365 container[dstLower] = prefix[0];
1366 container[dstUpper] = prefix[srcUpper];
1367
1368 if (len > 2)
1369 container[++dstLower] = prefix[1];
1370 if (len == 4)
1371 container[--dstUpper] = prefix[2];
1372 } else
1373 System.arraycopy(prefix, 0, container, startIndex, len);
1374 }
1375
1376 /**
1377 * Appends the passed {@code suffix} chars to given result
1378 * {@code container}. Updates {@code fastPathData.lastFreeIndex}
1379 * accordingly.
1380 *
1381 * @param suffix The suffix characters to append to result.
1382 * @param len The number of chars to append.
1383 * @param container Char array container which to append the suffix
1384 */
1385 private void appendSuffix(char[] suffix,
1386 int len,
1387 char[] container) {
1388
1389 int startIndex = fastPathData.lastFreeIndex;
1390
1391 // If suffix to append is only 1 char long, just assigns this char.
1392 // If suffix is less or equal 4, we use a dedicated algorithm that
1393 // has shown to run faster than System.arraycopy.
1394 // If more than 4, we use System.arraycopy.
1395 if (len == 1)
1396 container[startIndex] = suffix[0];
1397 else if (len <= 4) {
1398 int dstLower = startIndex;
1399 int dstUpper = dstLower + len - 1;
1400 int srcUpper = len - 1;
1401 container[dstLower] = suffix[0];
1402 container[dstUpper] = suffix[srcUpper];
1403
1404 if (len > 2)
1405 container[++dstLower] = suffix[1];
1406 if (len == 4)
1407 container[--dstUpper] = suffix[2];
1408 } else
1409 System.arraycopy(suffix, 0, container, startIndex, len);
1410
1411 fastPathData.lastFreeIndex += len;
1412 }
1413
1414 /**
1415 * Converts digit chars from {@code digitsBuffer} to current locale.
1416 *
1417 * Must be called before adding affixes since we refer to
1418 * {@code fastPathData.firstUsedIndex} and {@code fastPathData.lastFreeIndex},
1419 * and do not support affixes (for speed reason).
1420 *
1421 * We loop backward starting from last used index in {@code fastPathData}.
1422 *
1423 * @param digitsBuffer The char array container where the digits are stored.
1424 */
1425 private void localizeDigits(char[] digitsBuffer) {
1426
1427 // We will localize only the digits, using the groupingSize,
1428 // and taking into account fractional part.
1429
1430 // First take into account fractional part.
1431 int digitsCounter =
1432 fastPathData.lastFreeIndex - fastPathData.fractionalFirstIndex;
1433
1434 // The case when there is no fractional digits.
1435 if (digitsCounter < 0)
1436 digitsCounter = groupingSize;
1437
1438 // Only the digits remains to localize.
1439 for (int cursor = fastPathData.lastFreeIndex - 1;
1440 cursor >= fastPathData.firstUsedIndex;
1441 cursor--) {
1442 if (digitsCounter != 0) {
1443 // This is a digit char, we must localize it.
1444 digitsBuffer[cursor] += fastPathData.zeroDelta;
1445 digitsCounter--;
1446 } else {
1447 // Decimal separator or grouping char. Reinit counter only.
1448 digitsCounter = groupingSize;
1449 }
1450 }
1451 }
1452
1453 /**
1454 * This is the main entry point for the fast-path format algorithm.
1455 *
1456 * At this point we are sure to be in the expected conditions to run it.
1457 * This algorithm builds the formatted result and puts it in the dedicated
1458 * {@code fastPathData.fastPathContainer}.
1459 *
1460 * @param d the double value to be formatted.
1461 * @param negative Flag precising if {@code d} is negative.
1462 */
1463 private void fastDoubleFormat(double d,
1464 boolean negative) {
1465
1466 char[] container = fastPathData.fastPathContainer;
1467
1468 /*
1469 * The principle of the algorithm is to :
1470 * - Break the passed double into its integral and fractional parts
1471 * converted into integers.
1472 * - Then decide if rounding up must be applied or not by following
1473 * the half-even rounding rule, first using approximated scaled
1474 * fractional part.
1475 * - For the difficult cases (approximated scaled fractional part
1476 * being exactly 0.5d), we refine the rounding decision by calling
1477 * exactRoundUp utility method that both calculates the exact roundoff
1478 * on the approximation and takes correct rounding decision.
1479 * - We round-up the fractional part if needed, possibly propagating the
1480 * rounding to integral part if we meet a "all-nine" case for the
1481 * scaled fractional part.
1482 * - We then collect digits from the resulting integral and fractional
1483 * parts, also setting the required grouping chars on the fly.
1484 * - Then we localize the collected digits if needed, and
1485 * - Finally prepend/append prefix/suffix if any is needed.
1486 */
1487
1488 // Exact integral part of d.
1489 int integralPartAsInt = (int) d;
1490
1491 // Exact fractional part of d (since we subtract it's integral part).
1492 double exactFractionalPart = d - (double) integralPartAsInt;
1493
1494 // Approximated scaled fractional part of d (due to multiplication).
1495 double scaledFractional =
1496 exactFractionalPart * fastPathData.fractionalScaleFactor;
1497
1498 // Exact integral part of scaled fractional above.
1499 int fractionalPartAsInt = (int) scaledFractional;
1500
1501 // Exact fractional part of scaled fractional above.
1502 scaledFractional = scaledFractional - (double) fractionalPartAsInt;
1503
1504 // Only when scaledFractional is exactly 0.5d do we have to do exact
1505 // calculations and take fine-grained rounding decision, since
1506 // approximated results above may lead to incorrect decision.
1507 // Otherwise comparing against 0.5d (strictly greater or less) is ok.
1508 boolean roundItUp = false;
1509 if (scaledFractional >= 0.5d) {
1510 if (scaledFractional == 0.5d)
1511 // Rounding need fine-grained decision.
1512 roundItUp = exactRoundUp(exactFractionalPart, fractionalPartAsInt);
1513 else
1514 roundItUp = true;
1515
1516 if (roundItUp) {
1517 // Rounds up both fractional part (and also integral if needed).
1518 if (fractionalPartAsInt < fastPathData.fractionalMaxIntBound) {
1519 fractionalPartAsInt++;
1520 } else {
1521 // Propagates rounding to integral part since "all nines" case.
1522 fractionalPartAsInt = 0;
1523 integralPartAsInt++;
1524 }
1525 }
1526 }
1527
1528 // Collecting digits.
1529 collectFractionalDigits(fractionalPartAsInt, container,
1530 fastPathData.fractionalFirstIndex);
1531 collectIntegralDigits(integralPartAsInt, container,
1532 fastPathData.integralLastIndex);
1533
1534 // Localizing digits.
1535 if (fastPathData.zeroDelta != 0)
1536 localizeDigits(container);
1537
1538 // Adding prefix and suffix.
1539 if (negative) {
1540 if (fastPathData.negativeAffixesRequired)
1541 addAffixes(container,
1542 fastPathData.charsNegativePrefix,
1543 fastPathData.charsNegativeSuffix);
1544 } else if (fastPathData.positiveAffixesRequired)
1545 addAffixes(container,
1546 fastPathData.charsPositivePrefix,
1547 fastPathData.charsPositiveSuffix);
1548 }
1549
1550 /**
1551 * A fast-path shortcut of format(double) to be called by NumberFormat, or by
1552 * format(double, ...) public methods.
1553 *
1554 * If instance can be applied fast-path and passed double is not NaN or
1555 * Infinity, is in the integer range, we call {@code fastDoubleFormat}
1556 * after changing {@code d} to its positive value if necessary.
1557 *
1558 * Otherwise returns null by convention since fast-path can't be exercized.
1559 *
1560 * @param d The double value to be formatted
1561 *
1562 * @return the formatted result for {@code d} as a string.
1563 */
1564 String fastFormat(double d) {
1565 boolean isDataSet = false;
1566 // (Re-)Evaluates fast-path status if needed.
1567 if (fastPathCheckNeeded) {
1568 isDataSet = checkAndSetFastPathStatus();
1569 }
1570
1571 if (!isFastPath )
1572 // DecimalFormat instance is not in a fast-path state.
1573 return null;
1574
1575 if (!Double.isFinite(d))
1576 // Should not use fast-path for Infinity and NaN.
1577 return null;
1578
1579 // Extracts and records sign of double value, possibly changing it
1580 // to a positive one, before calling fastDoubleFormat().
1581 boolean negative = false;
1582 if (d < 0.0d) {
1583 negative = true;
1584 d = -d;
1585 } else if (d == 0.0d) {
1586 negative = (Math.copySign(1.0d, d) == -1.0d);
1587 d = +0.0d;
1588 }
1589
1590 if (d > MAX_INT_AS_DOUBLE)
1591 // Filters out values that are outside expected fast-path range
1592 return null;
1593 else {
1594 if (!isDataSet) {
1595 /*
1596 * If the fast path data is not set through
1597 * checkAndSetFastPathStatus() and fulfil the
1598 * fast path conditions then reset the data
1599 * directly through resetFastPathData()
1600 */
1601 resetFastPathData(isFastPath);
1602 }
1603 fastDoubleFormat(d, negative);
1604
1605 }
1606
1607
1608 // Returns a new string from updated fastPathContainer.
1609 return new String(fastPathData.fastPathContainer,
1610 fastPathData.firstUsedIndex,
1611 fastPathData.lastFreeIndex - fastPathData.firstUsedIndex);
1612
1613 }
1614
1615 // ======== End fast-path formating logic for double =========================
1616
1617 /**
1618 * Complete the formatting of a finite number. On entry, the digitList must
1619 * be filled in with the correct digits.
1620 */
1621 private StringBuffer subformat(StringBuffer result, FieldDelegate delegate,
1622 boolean isNegative, boolean isInteger,
1623 int maxIntDigits, int minIntDigits,
1624 int maxFraDigits, int minFraDigits) {
1625 // NOTE: This isn't required anymore because DigitList takes care of this.
1626 //
1627 // // The negative of the exponent represents the number of leading
1628 // // zeros between the decimal and the first non-zero digit, for
1629 // // a value < 0.1 (e.g., for 0.00123, -fExponent == 2). If this
1630 // // is more than the maximum fraction digits, then we have an underflow
1631 // // for the printed representation. We recognize this here and set
1632 // // the DigitList representation to zero in this situation.
1633 //
1634 // if (-digitList.decimalAt >= getMaximumFractionDigits())
1635 // {
1636 // digitList.count = 0;
1637 // }
1638
1639 char zero = symbols.getZeroDigit();
1640 int zeroDelta = zero - '0'; // '0' is the DigitList representation of zero
1641 char grouping = symbols.getGroupingSeparator();
1642 char decimal = isCurrencyFormat ?
1643 symbols.getMonetaryDecimalSeparator() :
1644 symbols.getDecimalSeparator();
1645
1646 /* Per bug 4147706, DecimalFormat must respect the sign of numbers which
1647 * format as zero. This allows sensible computations and preserves
1648 * relations such as signum(1/x) = signum(x), where x is +Infinity or
1649 * -Infinity. Prior to this fix, we always formatted zero values as if
1650 * they were positive. Liu 7/6/98.
1651 */
1652 if (digitList.isZero()) {
1653 digitList.decimalAt = 0; // Normalize
1654 }
1655
1656 if (isNegative) {
1657 append(result, negativePrefix, delegate,
1658 getNegativePrefixFieldPositions(), Field.SIGN);
1659 } else {
1660 append(result, positivePrefix, delegate,
1661 getPositivePrefixFieldPositions(), Field.SIGN);
1662 }
1663
1664 if (useExponentialNotation) {
1665 int iFieldStart = result.length();
1666 int iFieldEnd = -1;
1667 int fFieldStart = -1;
1668
1669 // Minimum integer digits are handled in exponential format by
1670 // adjusting the exponent. For example, 0.01234 with 3 minimum
1671 // integer digits is "123.4E-4".
1672
1673 // Maximum integer digits are interpreted as indicating the
1674 // repeating range. This is useful for engineering notation, in
1675 // which the exponent is restricted to a multiple of 3. For
1676 // example, 0.01234 with 3 maximum integer digits is "12.34e-3".
1677 // If maximum integer digits are > 1 and are larger than
1678 // minimum integer digits, then minimum integer digits are
1679 // ignored.
1680 int exponent = digitList.decimalAt;
1681 int repeat = maxIntDigits;
1682 int minimumIntegerDigits = minIntDigits;
1683 if (repeat > 1 && repeat > minIntDigits) {
1684 // A repeating range is defined; adjust to it as follows.
1685 // If repeat == 3, we have 6,5,4=>3; 3,2,1=>0; 0,-1,-2=>-3;
1686 // -3,-4,-5=>-6, etc. This takes into account that the
1687 // exponent we have here is off by one from what we expect;
1688 // it is for the format 0.MMMMMx10^n.
1689 if (exponent >= 1) {
1690 exponent = ((exponent - 1) / repeat) * repeat;
1691 } else {
1692 // integer division rounds towards 0
1693 exponent = ((exponent - repeat) / repeat) * repeat;
1694 }
1695 minimumIntegerDigits = 1;
1696 } else {
1697 // No repeating range is defined; use minimum integer digits.
1698 exponent -= minimumIntegerDigits;
1699 }
1700
1701 // We now output a minimum number of digits, and more if there
1702 // are more digits, up to the maximum number of digits. We
1703 // place the decimal point after the "integer" digits, which
1704 // are the first (decimalAt - exponent) digits.
1705 int minimumDigits = minIntDigits + minFraDigits;
1706 if (minimumDigits < 0) { // overflow?
1707 minimumDigits = Integer.MAX_VALUE;
1708 }
1709
1710 // The number of integer digits is handled specially if the number
1711 // is zero, since then there may be no digits.
1712 int integerDigits = digitList.isZero() ? minimumIntegerDigits :
1713 digitList.decimalAt - exponent;
1714 if (minimumDigits < integerDigits) {
1715 minimumDigits = integerDigits;
1716 }
1717 int totalDigits = digitList.count;
1718 if (minimumDigits > totalDigits) {
1719 totalDigits = minimumDigits;
1720 }
1721 boolean addedDecimalSeparator = false;
1722
1723 for (int i=0; i<totalDigits; ++i) {
1724 if (i == integerDigits) {
1725 // Record field information for caller.
1726 iFieldEnd = result.length();
1727
1728 result.append(decimal);
1729 addedDecimalSeparator = true;
1730
1731 // Record field information for caller.
1732 fFieldStart = result.length();
1733 }
1734 result.append((i < digitList.count) ?
1735 (char)(digitList.digits[i] + zeroDelta) :
1736 zero);
1737 }
1738
1739 if (decimalSeparatorAlwaysShown && totalDigits == integerDigits) {
1740 // Record field information for caller.
1741 iFieldEnd = result.length();
1742
1743 result.append(decimal);
1744 addedDecimalSeparator = true;
1745
1746 // Record field information for caller.
1747 fFieldStart = result.length();
1748 }
1749
1750 // Record field information
1751 if (iFieldEnd == -1) {
1752 iFieldEnd = result.length();
1753 }
1754 delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
1755 iFieldStart, iFieldEnd, result);
1756 if (addedDecimalSeparator) {
1757 delegate.formatted(Field.DECIMAL_SEPARATOR,
1758 Field.DECIMAL_SEPARATOR,
1759 iFieldEnd, fFieldStart, result);
1760 }
1761 if (fFieldStart == -1) {
1762 fFieldStart = result.length();
1763 }
1764 delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
1765 fFieldStart, result.length(), result);
1766
1767 // The exponent is output using the pattern-specified minimum
1768 // exponent digits. There is no maximum limit to the exponent
1769 // digits, since truncating the exponent would result in an
1770 // unacceptable inaccuracy.
1771 int fieldStart = result.length();
1772
1773 result.append(symbols.getExponentSeparator());
1774
1775 delegate.formatted(Field.EXPONENT_SYMBOL, Field.EXPONENT_SYMBOL,
1776 fieldStart, result.length(), result);
1777
1778 // For zero values, we force the exponent to zero. We
1779 // must do this here, and not earlier, because the value
1780 // is used to determine integer digit count above.
1781 if (digitList.isZero()) {
1782 exponent = 0;
1783 }
1784
1785 boolean negativeExponent = exponent < 0;
1786 if (negativeExponent) {
1787 exponent = -exponent;
1788 fieldStart = result.length();
1789 result.append(symbols.getMinusSign());
1790 delegate.formatted(Field.EXPONENT_SIGN, Field.EXPONENT_SIGN,
1791 fieldStart, result.length(), result);
1792 }
1793 digitList.set(negativeExponent, exponent);
1794
1795 int eFieldStart = result.length();
1796
1797 for (int i=digitList.decimalAt; i<minExponentDigits; ++i) {
1798 result.append(zero);
1799 }
1800 for (int i=0; i<digitList.decimalAt; ++i) {
1801 result.append((i < digitList.count) ?
1802 (char)(digitList.digits[i] + zeroDelta) : zero);
1803 }
1804 delegate.formatted(Field.EXPONENT, Field.EXPONENT, eFieldStart,
1805 result.length(), result);
1806 } else {
1807 int iFieldStart = result.length();
1808
1809 // Output the integer portion. Here 'count' is the total
1810 // number of integer digits we will display, including both
1811 // leading zeros required to satisfy getMinimumIntegerDigits,
1812 // and actual digits present in the number.
1813 int count = minIntDigits;
1814 int digitIndex = 0; // Index into digitList.fDigits[]
1815 if (digitList.decimalAt > 0 && count < digitList.decimalAt) {
1816 count = digitList.decimalAt;
1817 }
1818
1819 // Handle the case where getMaximumIntegerDigits() is smaller
1820 // than the real number of integer digits. If this is so, we
1821 // output the least significant max integer digits. For example,
1822 // the value 1997 printed with 2 max integer digits is just "97".
1823 if (count > maxIntDigits) {
1824 count = maxIntDigits;
1825 digitIndex = digitList.decimalAt - count;
1826 }
1827
1828 int sizeBeforeIntegerPart = result.length();
1829 for (int i=count-1; i>=0; --i) {
1830 if (i < digitList.decimalAt && digitIndex < digitList.count) {
1831 // Output a real digit
1832 result.append((char)(digitList.digits[digitIndex++] + zeroDelta));
1833 } else {
1834 // Output a leading zero
1835 result.append(zero);
1836 }
1837
1838 // Output grouping separator if necessary. Don't output a
1839 // grouping separator if i==0 though; that's at the end of
1840 // the integer part.
1841 if (isGroupingUsed() && i>0 && (groupingSize != 0) &&
1842 (i % groupingSize == 0)) {
1843 int gStart = result.length();
1844 result.append(grouping);
1845 delegate.formatted(Field.GROUPING_SEPARATOR,
1846 Field.GROUPING_SEPARATOR, gStart,
1847 result.length(), result);
1848 }
1849 }
1850
1851 // Determine whether or not there are any printable fractional
1852 // digits. If we've used up the digits we know there aren't.
1853 boolean fractionPresent = (minFraDigits > 0) ||
1854 (!isInteger && digitIndex < digitList.count);
1855
1856 // If there is no fraction present, and we haven't printed any
1857 // integer digits, then print a zero. Otherwise we won't print
1858 // _any_ digits, and we won't be able to parse this string.
1859 if (!fractionPresent && result.length() == sizeBeforeIntegerPart) {
1860 result.append(zero);
1861 }
1862
1863 delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
1864 iFieldStart, result.length(), result);
1865
1866 // Output the decimal separator if we always do so.
1867 int sStart = result.length();
1868 if (decimalSeparatorAlwaysShown || fractionPresent) {
1869 result.append(decimal);
1870 }
1871
1872 if (sStart != result.length()) {
1873 delegate.formatted(Field.DECIMAL_SEPARATOR,
1874 Field.DECIMAL_SEPARATOR,
1875 sStart, result.length(), result);
1876 }
1877 int fFieldStart = result.length();
1878
1879 for (int i=0; i < maxFraDigits; ++i) {
1880 // Here is where we escape from the loop. We escape if we've
1881 // output the maximum fraction digits (specified in the for
1882 // expression above).
1883 // We also stop when we've output the minimum digits and either:
1884 // we have an integer, so there is no fractional stuff to
1885 // display, or we're out of significant digits.
1886 if (i >= minFraDigits &&
1887 (isInteger || digitIndex >= digitList.count)) {
1888 break;
1889 }
1890
1891 // Output leading fractional zeros. These are zeros that come
1892 // after the decimal but before any significant digits. These
1893 // are only output if abs(number being formatted) < 1.0.
1894 if (-1-i > (digitList.decimalAt-1)) {
1895 result.append(zero);
1896 continue;
1897 }
1898
1899 // Output a digit, if we have any precision left, or a
1900 // zero if we don't. We don't want to output noise digits.
1901 if (!isInteger && digitIndex < digitList.count) {
1902 result.append((char)(digitList.digits[digitIndex++] + zeroDelta));
1903 } else {
1904 result.append(zero);
1905 }
1906 }
1907
1908 // Record field information for caller.
1909 delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
1910 fFieldStart, result.length(), result);
1911 }
1912
1913 if (isNegative) {
1914 append(result, negativeSuffix, delegate,
1915 getNegativeSuffixFieldPositions(), Field.SIGN);
1916 } else {
1917 append(result, positiveSuffix, delegate,
1918 getPositiveSuffixFieldPositions(), Field.SIGN);
1919 }
1920
1921 return result;
1922 }
1923
1924 /**
1925 * Appends the String <code>string</code> to <code>result</code>.
1926 * <code>delegate</code> is notified of all the
1927 * <code>FieldPosition</code>s in <code>positions</code>.
1928 * <p>
1929 * If one of the <code>FieldPosition</code>s in <code>positions</code>
1930 * identifies a <code>SIGN</code> attribute, it is mapped to
1931 * <code>signAttribute</code>. This is used
1932 * to map the <code>SIGN</code> attribute to the <code>EXPONENT</code>
1933 * attribute as necessary.
1934 * <p>
1935 * This is used by <code>subformat</code> to add the prefix/suffix.
1936 */
1937 private void append(StringBuffer result, String string,
1938 FieldDelegate delegate,
1939 FieldPosition[] positions,
1940 Format.Field signAttribute) {
1941 int start = result.length();
1942
1943 if (string.length() > 0) {
1944 result.append(string);
1945 for (int counter = 0, max = positions.length; counter < max;
1946 counter++) {
1947 FieldPosition fp = positions[counter];
1948 Format.Field attribute = fp.getFieldAttribute();
1949
1950 if (attribute == Field.SIGN) {
1951 attribute = signAttribute;
1952 }
1953 delegate.formatted(attribute, attribute,
1954 start + fp.getBeginIndex(),
1955 start + fp.getEndIndex(), result);
1956 }
1957 }
1958 }
1959
1960 /**
1961 * Parses text from a string to produce a <code>Number</code>.
1962 * <p>
1963 * The method attempts to parse text starting at the index given by
1964 * <code>pos</code>.
1965 * If parsing succeeds, then the index of <code>pos</code> is updated
1966 * to the index after the last character used (parsing does not necessarily
1967 * use all characters up to the end of the string), and the parsed
1968 * number is returned. The updated <code>pos</code> can be used to
1969 * indicate the starting point for the next call to this method.
1970 * If an error occurs, then the index of <code>pos</code> is not
1971 * changed, the error index of <code>pos</code> is set to the index of
1972 * the character where the error occurred, and null is returned.
1973 * <p>
1974 * The subclass returned depends on the value of {@link #isParseBigDecimal}
1975 * as well as on the string being parsed.
1976 * <ul>
1977 * <li>If <code>isParseBigDecimal()</code> is false (the default),
1978 * most integer values are returned as <code>Long</code>
1979 * objects, no matter how they are written: <code>"17"</code> and
1980 * <code>"17.000"</code> both parse to <code>Long(17)</code>.
1981 * Values that cannot fit into a <code>Long</code> are returned as
1982 * <code>Double</code>s. This includes values with a fractional part,
1983 * infinite values, <code>NaN</code>, and the value -0.0.
1984 * <code>DecimalFormat</code> does <em>not</em> decide whether to
1985 * return a <code>Double</code> or a <code>Long</code> based on the
1986 * presence of a decimal separator in the source string. Doing so
1987 * would prevent integers that overflow the mantissa of a double,
1988 * such as <code>"-9,223,372,036,854,775,808.00"</code>, from being
1989 * parsed accurately.
1990 * <p>
1991 * Callers may use the <code>Number</code> methods
1992 * <code>doubleValue</code>, <code>longValue</code>, etc., to obtain
1993 * the type they want.
1994 * <li>If <code>isParseBigDecimal()</code> is true, values are returned
1995 * as <code>BigDecimal</code> objects. The values are the ones
1996 * constructed by {@link java.math.BigDecimal#BigDecimal(String)}
1997 * for corresponding strings in locale-independent format. The
1998 * special cases negative and positive infinity and NaN are returned
1999 * as <code>Double</code> instances holding the values of the
2000 * corresponding <code>Double</code> constants.
2001 * </ul>
2002 * <p>
2003 * <code>DecimalFormat</code> parses all Unicode characters that represent
2004 * decimal digits, as defined by <code>Character.digit()</code>. In
2005 * addition, <code>DecimalFormat</code> also recognizes as digits the ten
2006 * consecutive characters starting with the localized zero digit defined in
2007 * the <code>DecimalFormatSymbols</code> object.
2008 *
2009 * @param text the string to be parsed
2010 * @param pos A <code>ParsePosition</code> object with index and error
2011 * index information as described above.
2012 * @return the parsed value, or <code>null</code> if the parse fails
2013 * @exception NullPointerException if <code>text</code> or
2014 * <code>pos</code> is null.
2015 */
2016 @Override
2017 public Number parse(String text, ParsePosition pos) {
2018 // special case NaN
2019 if (text.regionMatches(pos.index, symbols.getNaN(), 0, symbols.getNaN().length())) {
2020 pos.index = pos.index + symbols.getNaN().length();
2021 return Double.valueOf(Double.NaN);
2022 }
2023
2024 boolean[] status = new boolean[STATUS_LENGTH];
2025 if (!subparse(text, pos, positivePrefix, negativePrefix, digitList, false, status)) {
2026 return null;
2027 }
2028
2029 // special case INFINITY
2030 if (status[STATUS_INFINITE]) {
2031 if (status[STATUS_POSITIVE] == (multiplier >= 0)) {
2032 return Double.valueOf(Double.POSITIVE_INFINITY);
2033 } else {
2034 return Double.valueOf(Double.NEGATIVE_INFINITY);
2035 }
2036 }
2037
2038 if (multiplier == 0) {
2039 if (digitList.isZero()) {
2040 return Double.valueOf(Double.NaN);
2041 } else if (status[STATUS_POSITIVE]) {
2042 return Double.valueOf(Double.POSITIVE_INFINITY);
2043 } else {
2044 return Double.valueOf(Double.NEGATIVE_INFINITY);
2045 }
2046 }
2047
2048 if (isParseBigDecimal()) {
2049 BigDecimal bigDecimalResult = digitList.getBigDecimal();
2050
2051 if (multiplier != 1) {
2052 try {
2053 bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier());
2054 }
2055 catch (ArithmeticException e) { // non-terminating decimal expansion
2056 bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier(), roundingMode);
2057 }
2058 }
2059
2060 if (!status[STATUS_POSITIVE]) {
2061 bigDecimalResult = bigDecimalResult.negate();
2062 }
2063 return bigDecimalResult;
2064 } else {
2065 boolean gotDouble = true;
2066 boolean gotLongMinimum = false;
2067 double doubleResult = 0.0;
2068 long longResult = 0;
2069
2070 // Finally, have DigitList parse the digits into a value.
2071 if (digitList.fitsIntoLong(status[STATUS_POSITIVE], isParseIntegerOnly())) {
2072 gotDouble = false;
2073 longResult = digitList.getLong();
2074 if (longResult < 0) { // got Long.MIN_VALUE
2075 gotLongMinimum = true;
2076 }
2077 } else {
2078 doubleResult = digitList.getDouble();
2079 }
2080
2081 // Divide by multiplier. We have to be careful here not to do
2082 // unneeded conversions between double and long.
2083 if (multiplier != 1) {
2084 if (gotDouble) {
2085 doubleResult /= multiplier;
2086 } else {
2087 // Avoid converting to double if we can
2088 if (longResult % multiplier == 0) {
2089 longResult /= multiplier;
2090 } else {
2091 doubleResult = ((double)longResult) / multiplier;
2092 gotDouble = true;
2093 }
2094 }
2095 }
2096
2097 if (!status[STATUS_POSITIVE] && !gotLongMinimum) {
2098 doubleResult = -doubleResult;
2099 longResult = -longResult;
2100 }
2101
2102 // At this point, if we divided the result by the multiplier, the
2103 // result may fit into a long. We check for this case and return
2104 // a long if possible.
2105 // We must do this AFTER applying the negative (if appropriate)
2106 // in order to handle the case of LONG_MIN; otherwise, if we do
2107 // this with a positive value -LONG_MIN, the double is > 0, but
2108 // the long is < 0. We also must retain a double in the case of
2109 // -0.0, which will compare as == to a long 0 cast to a double
2110 // (bug 4162852).
2111 if (multiplier != 1 && gotDouble) {
2112 longResult = (long)doubleResult;
2113 gotDouble = ((doubleResult != (double)longResult) ||
2114 (doubleResult == 0.0 && 1/doubleResult < 0.0)) &&
2115 !isParseIntegerOnly();
2116 }
2117
2118 // cast inside of ?: because of binary numeric promotion, JLS 15.25
2119 return gotDouble ? (Number)doubleResult : (Number)longResult;
2120 }
2121 }
2122
2123 /**
2124 * Return a BigInteger multiplier.
2125 */
2126 private BigInteger getBigIntegerMultiplier() {
2127 if (bigIntegerMultiplier == null) {
2128 bigIntegerMultiplier = BigInteger.valueOf(multiplier);
2129 }
2130 return bigIntegerMultiplier;
2131 }
2132 private transient BigInteger bigIntegerMultiplier;
2133
2134 /**
2135 * Return a BigDecimal multiplier.
2136 */
2137 private BigDecimal getBigDecimalMultiplier() {
2138 if (bigDecimalMultiplier == null) {
2139 bigDecimalMultiplier = new BigDecimal(multiplier);
2140 }
2141 return bigDecimalMultiplier;
2142 }
2143 private transient BigDecimal bigDecimalMultiplier;
2144
2145 private static final int STATUS_INFINITE = 0;
2146 private static final int STATUS_POSITIVE = 1;
2147 private static final int STATUS_LENGTH = 2;
2148
2149 /**
2150 * Parse the given text into a number. The text is parsed beginning at
2151 * parsePosition, until an unparseable character is seen.
2152 * @param text The string to parse.
2153 * @param parsePosition The position at which to being parsing. Upon
2154 * return, the first unparseable character.
2155 * @param digits The DigitList to set to the parsed value.
2156 * @param isExponent If true, parse an exponent. This means no
2157 * infinite values and integer only.
2158 * @param status Upon return contains boolean status flags indicating
2159 * whether the value was infinite and whether it was positive.
2160 */
2161 private final boolean subparse(String text, ParsePosition parsePosition,
2162 String positivePrefix, String negativePrefix,
2163 DigitList digits, boolean isExponent,
2164 boolean status[]) {
2165 int position = parsePosition.index;
2166 int oldStart = parsePosition.index;
2167 int backup;
2168 boolean gotPositive, gotNegative;
2169
2170 // check for positivePrefix; take longest
2171 gotPositive = text.regionMatches(position, positivePrefix, 0,
2172 positivePrefix.length());
2173 gotNegative = text.regionMatches(position, negativePrefix, 0,
2174 negativePrefix.length());
2175
2176 if (gotPositive && gotNegative) {
2177 if (positivePrefix.length() > negativePrefix.length()) {
2178 gotNegative = false;
2179 } else if (positivePrefix.length() < negativePrefix.length()) {
2180 gotPositive = false;
2181 }
2182 }
2183
2184 if (gotPositive) {
2185 position += positivePrefix.length();
2186 } else if (gotNegative) {
2187 position += negativePrefix.length();
2188 } else {
2189 parsePosition.errorIndex = position;
2190 return false;
2191 }
2192
2193 // process digits or Inf, find decimal position
2194 status[STATUS_INFINITE] = false;
2195 if (!isExponent && text.regionMatches(position,symbols.getInfinity(),0,
2196 symbols.getInfinity().length())) {
2197 position += symbols.getInfinity().length();
2198 status[STATUS_INFINITE] = true;
2199 } else {
2200 // We now have a string of digits, possibly with grouping symbols,
2201 // and decimal points. We want to process these into a DigitList.
2202 // We don't want to put a bunch of leading zeros into the DigitList
2203 // though, so we keep track of the location of the decimal point,
2204 // put only significant digits into the DigitList, and adjust the
2205 // exponent as needed.
2206
2207 digits.decimalAt = digits.count = 0;
2208 char zero = symbols.getZeroDigit();
2209 char decimal = isCurrencyFormat ?
2210 symbols.getMonetaryDecimalSeparator() :
2211 symbols.getDecimalSeparator();
2212 char grouping = symbols.getGroupingSeparator();
2213 String exponentString = symbols.getExponentSeparator();
2214 boolean sawDecimal = false;
2215 boolean sawExponent = false;
2216 boolean sawDigit = false;
2217 int exponent = 0; // Set to the exponent value, if any
2218
2219 // We have to track digitCount ourselves, because digits.count will
2220 // pin when the maximum allowable digits is reached.
2221 int digitCount = 0;
2222
2223 backup = -1;
2224 for (; position < text.length(); ++position) {
2225 char ch = text.charAt(position);
2226
2227 /* We recognize all digit ranges, not only the Latin digit range
2228 * '0'..'9'. We do so by using the Character.digit() method,
2229 * which converts a valid Unicode digit to the range 0..9.
2230 *
2231 * The character 'ch' may be a digit. If so, place its value
2232 * from 0 to 9 in 'digit'. First try using the locale digit,
2233 * which may or MAY NOT be a standard Unicode digit range. If
2234 * this fails, try using the standard Unicode digit ranges by
2235 * calling Character.digit(). If this also fails, digit will
2236 * have a value outside the range 0..9.
2237 */
2238 int digit = ch - zero;
2239 if (digit < 0 || digit > 9) {
2240 digit = Character.digit(ch, 10);
2241 }
2242
2243 if (digit == 0) {
2244 // Cancel out backup setting (see grouping handler below)
2245 backup = -1; // Do this BEFORE continue statement below!!!
2246 sawDigit = true;
2247
2248 // Handle leading zeros
2249 if (digits.count == 0) {
2250 // Ignore leading zeros in integer part of number.
2251 if (!sawDecimal) {
2252 continue;
2253 }
2254
2255 // If we have seen the decimal, but no significant
2256 // digits yet, then we account for leading zeros by
2257 // decrementing the digits.decimalAt into negative
2258 // values.
2259 --digits.decimalAt;
2260 } else {
2261 ++digitCount;
2262 digits.append((char)(digit + '0'));
2263 }
2264 } else if (digit > 0 && digit <= 9) { // [sic] digit==0 handled above
2265 sawDigit = true;
2266 ++digitCount;
2267 digits.append((char)(digit + '0'));
2268
2269 // Cancel out backup setting (see grouping handler below)
2270 backup = -1;
2271 } else if (!isExponent && ch == decimal) {
2272 // If we're only parsing integers, or if we ALREADY saw the
2273 // decimal, then don't parse this one.
2274 if (isParseIntegerOnly() || sawDecimal) {
2275 break;
2276 }
2277 digits.decimalAt = digitCount; // Not digits.count!
2278 sawDecimal = true;
2279 } else if (!isExponent && ch == grouping && isGroupingUsed()) {
2280 if (sawDecimal) {
2281 break;
2282 }
2283 // Ignore grouping characters, if we are using them, but
2284 // require that they be followed by a digit. Otherwise
2285 // we backup and reprocess them.
2286 backup = position;
2287 } else if (!isExponent && text.regionMatches(position, exponentString, 0, exponentString.length())
2288 && !sawExponent) {
2289 // Process the exponent by recursively calling this method.
2290 ParsePosition pos = new ParsePosition(position + exponentString.length());
2291 boolean[] stat = new boolean[STATUS_LENGTH];
2292 DigitList exponentDigits = new DigitList();
2293
2294 if (subparse(text, pos, "", Character.toString(symbols.getMinusSign()), exponentDigits, true, stat) &&
2295 exponentDigits.fitsIntoLong(stat[STATUS_POSITIVE], true)) {
2296 position = pos.index; // Advance past the exponent
2297 exponent = (int)exponentDigits.getLong();
2298 if (!stat[STATUS_POSITIVE]) {
2299 exponent = -exponent;
2300 }
2301 sawExponent = true;
2302 }
2303 break; // Whether we fail or succeed, we exit this loop
2304 } else {
2305 break;
2306 }
2307 }
2308
2309 if (backup != -1) {
2310 position = backup;
2311 }
2312
2313 // If there was no decimal point we have an integer
2314 if (!sawDecimal) {
2315 digits.decimalAt = digitCount; // Not digits.count!
2316 }
2317
2318 // Adjust for exponent, if any
2319 digits.decimalAt += exponent;
2320
2321 // If none of the text string was recognized. For example, parse
2322 // "x" with pattern "#0.00" (return index and error index both 0)
2323 // parse "$" with pattern "$#0.00". (return index 0 and error
2324 // index 1).
2325 if (!sawDigit && digitCount == 0) {
2326 parsePosition.index = oldStart;
2327 parsePosition.errorIndex = oldStart;
2328 return false;
2329 }
2330 }
2331
2332 // check for suffix
2333 if (!isExponent) {
2334 if (gotPositive) {
2335 gotPositive = text.regionMatches(position,positiveSuffix,0,
2336 positiveSuffix.length());
2337 }
2338 if (gotNegative) {
2339 gotNegative = text.regionMatches(position,negativeSuffix,0,
2340 negativeSuffix.length());
2341 }
2342
2343 // if both match, take longest
2344 if (gotPositive && gotNegative) {
2345 if (positiveSuffix.length() > negativeSuffix.length()) {
2346 gotNegative = false;
2347 } else if (positiveSuffix.length() < negativeSuffix.length()) {
2348 gotPositive = false;
2349 }
2350 }
2351
2352 // fail if neither or both
2353 if (gotPositive == gotNegative) {
2354 parsePosition.errorIndex = position;
2355 return false;
2356 }
2357
2358 parsePosition.index = position +
2359 (gotPositive ? positiveSuffix.length() : negativeSuffix.length()); // mark success!
2360 } else {
2361 parsePosition.index = position;
2362 }
2363
2364 status[STATUS_POSITIVE] = gotPositive;
2365 if (parsePosition.index == oldStart) {
2366 parsePosition.errorIndex = position;
2367 return false;
2368 }
2369 return true;
2370 }
2371
2372 /**
2373 * Returns a copy of the decimal format symbols, which is generally not
2374 * changed by the programmer or user.
2375 * @return a copy of the desired DecimalFormatSymbols
2376 * @see java.text.DecimalFormatSymbols
2377 */
2378 public DecimalFormatSymbols getDecimalFormatSymbols() {
2379 try {
2380 // don't allow multiple references
2381 return (DecimalFormatSymbols) symbols.clone();
2382 } catch (Exception foo) {
2383 return null; // should never happen
2384 }
2385 }
2386
2387
2388 /**
2389 * Sets the decimal format symbols, which is generally not changed
2390 * by the programmer or user.
2391 * @param newSymbols desired DecimalFormatSymbols
2392 * @see java.text.DecimalFormatSymbols
2393 */
2394 public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols) {
2395 try {
2396 // don't allow multiple references
2397 symbols = (DecimalFormatSymbols) newSymbols.clone();
2398 expandAffixes();
2399 fastPathCheckNeeded = true;
2400 } catch (Exception foo) {
2401 // should never happen
2402 }
2403 }
2404
2405 /**
2406 * Get the positive prefix.
2407 * <P>Examples: +123, $123, sFr123
2408 *
2409 * @return the positive prefix
2410 */
2411 public String getPositivePrefix () {
2412 return positivePrefix;
2413 }
2414
2415 /**
2416 * Set the positive prefix.
2417 * <P>Examples: +123, $123, sFr123
2418 *
2419 * @param newValue the new positive prefix
2420 */
2421 public void setPositivePrefix (String newValue) {
2422 positivePrefix = newValue;
2423 posPrefixPattern = null;
2424 positivePrefixFieldPositions = null;
2425 fastPathCheckNeeded = true;
2426 }
2427
2428 /**
2429 * Returns the FieldPositions of the fields in the prefix used for
2430 * positive numbers. This is not used if the user has explicitly set
2431 * a positive prefix via <code>setPositivePrefix</code>. This is
2432 * lazily created.
2433 *
2434 * @return FieldPositions in positive prefix
2435 */
2436 private FieldPosition[] getPositivePrefixFieldPositions() {
2437 if (positivePrefixFieldPositions == null) {
2438 if (posPrefixPattern != null) {
2439 positivePrefixFieldPositions = expandAffix(posPrefixPattern);
2440 } else {
2441 positivePrefixFieldPositions = EmptyFieldPositionArray;
2442 }
2443 }
2444 return positivePrefixFieldPositions;
2445 }
2446
2447 /**
2448 * Get the negative prefix.
2449 * <P>Examples: -123, ($123) (with negative suffix), sFr-123
2450 *
2451 * @return the negative prefix
2452 */
2453 public String getNegativePrefix () {
2454 return negativePrefix;
2455 }
2456
2457 /**
2458 * Set the negative prefix.
2459 * <P>Examples: -123, ($123) (with negative suffix), sFr-123
2460 *
2461 * @param newValue the new negative prefix
2462 */
2463 public void setNegativePrefix (String newValue) {
2464 negativePrefix = newValue;
2465 negPrefixPattern = null;
2466 fastPathCheckNeeded = true;
2467 }
2468
2469 /**
2470 * Returns the FieldPositions of the fields in the prefix used for
2471 * negative numbers. This is not used if the user has explicitly set
2472 * a negative prefix via <code>setNegativePrefix</code>. This is
2473 * lazily created.
2474 *
2475 * @return FieldPositions in positive prefix
2476 */
2477 private FieldPosition[] getNegativePrefixFieldPositions() {
2478 if (negativePrefixFieldPositions == null) {
2479 if (negPrefixPattern != null) {
2480 negativePrefixFieldPositions = expandAffix(negPrefixPattern);
2481 } else {
2482 negativePrefixFieldPositions = EmptyFieldPositionArray;
2483 }
2484 }
2485 return negativePrefixFieldPositions;
2486 }
2487
2488 /**
2489 * Get the positive suffix.
2490 * <P>Example: 123%
2491 *
2492 * @return the positive suffix
2493 */
2494 public String getPositiveSuffix () {
2495 return positiveSuffix;
2496 }
2497
2498 /**
2499 * Set the positive suffix.
2500 * <P>Example: 123%
2501 *
2502 * @param newValue the new positive suffix
2503 */
2504 public void setPositiveSuffix (String newValue) {
2505 positiveSuffix = newValue;
2506 posSuffixPattern = null;
2507 fastPathCheckNeeded = true;
2508 }
2509
2510 /**
2511 * Returns the FieldPositions of the fields in the suffix used for
2512 * positive numbers. This is not used if the user has explicitly set
2513 * a positive suffix via <code>setPositiveSuffix</code>. This is
2514 * lazily created.
2515 *
2516 * @return FieldPositions in positive prefix
2517 */
2518 private FieldPosition[] getPositiveSuffixFieldPositions() {
2519 if (positiveSuffixFieldPositions == null) {
2520 if (posSuffixPattern != null) {
2521 positiveSuffixFieldPositions = expandAffix(posSuffixPattern);
2522 } else {
2523 positiveSuffixFieldPositions = EmptyFieldPositionArray;
2524 }
2525 }
2526 return positiveSuffixFieldPositions;
2527 }
2528
2529 /**
2530 * Get the negative suffix.
2531 * <P>Examples: -123%, ($123) (with positive suffixes)
2532 *
2533 * @return the negative suffix
2534 */
2535 public String getNegativeSuffix () {
2536 return negativeSuffix;
2537 }
2538
2539 /**
2540 * Set the negative suffix.
2541 * <P>Examples: 123%
2542 *
2543 * @param newValue the new negative suffix
2544 */
2545 public void setNegativeSuffix (String newValue) {
2546 negativeSuffix = newValue;
2547 negSuffixPattern = null;
2548 fastPathCheckNeeded = true;
2549 }
2550
2551 /**
2552 * Returns the FieldPositions of the fields in the suffix used for
2553 * negative numbers. This is not used if the user has explicitly set
2554 * a negative suffix via <code>setNegativeSuffix</code>. This is
2555 * lazily created.
2556 *
2557 * @return FieldPositions in positive prefix
2558 */
2559 private FieldPosition[] getNegativeSuffixFieldPositions() {
2560 if (negativeSuffixFieldPositions == null) {
2561 if (negSuffixPattern != null) {
2562 negativeSuffixFieldPositions = expandAffix(negSuffixPattern);
2563 } else {
2564 negativeSuffixFieldPositions = EmptyFieldPositionArray;
2565 }
2566 }
2567 return negativeSuffixFieldPositions;
2568 }
2569
2570 /**
2571 * Gets the multiplier for use in percent, per mille, and similar
2572 * formats.
2573 *
2574 * @return the multiplier
2575 * @see #setMultiplier(int)
2576 */
2577 public int getMultiplier () {
2578 return multiplier;
2579 }
2580
2581 /**
2582 * Sets the multiplier for use in percent, per mille, and similar
2583 * formats.
2584 * For a percent format, set the multiplier to 100 and the suffixes to
2585 * have '%' (for Arabic, use the Arabic percent sign).
2586 * For a per mille format, set the multiplier to 1000 and the suffixes to
2587 * have '\u2030'.
2588 *
2589 * <P>Example: with multiplier 100, 1.23 is formatted as "123", and
2590 * "123" is parsed into 1.23.
2591 *
2592 * @param newValue the new multiplier
2593 * @see #getMultiplier
2594 */
2595 public void setMultiplier (int newValue) {
2596 multiplier = newValue;
2597 bigDecimalMultiplier = null;
2598 bigIntegerMultiplier = null;
2599 fastPathCheckNeeded = true;
2600 }
2601
2602 /**
2603 * {@inheritDoc}
2604 */
2605 @Override
2606 public void setGroupingUsed(boolean newValue) {
2607 super.setGroupingUsed(newValue);
2608 fastPathCheckNeeded = true;
2609 }
2610
2611 /**
2612 * Return the grouping size. Grouping size is the number of digits between
2613 * grouping separators in the integer portion of a number. For example,
2614 * in the number "123,456.78", the grouping size is 3.
2615 *
2616 * @return the grouping size
2617 * @see #setGroupingSize
2618 * @see java.text.NumberFormat#isGroupingUsed
2619 * @see java.text.DecimalFormatSymbols#getGroupingSeparator
2620 */
2621 public int getGroupingSize () {
2622 return groupingSize;
2623 }
2624
2625 /**
2626 * Set the grouping size. Grouping size is the number of digits between
2627 * grouping separators in the integer portion of a number. For example,
2628 * in the number "123,456.78", the grouping size is 3.
2629 * <br>
2630 * The value passed in is converted to a byte, which may lose information.
2631 *
2632 * @param newValue the new grouping size
2633 * @see #getGroupingSize
2634 * @see java.text.NumberFormat#setGroupingUsed
2635 * @see java.text.DecimalFormatSymbols#setGroupingSeparator
2636 */
2637 public void setGroupingSize (int newValue) {
2638 groupingSize = (byte)newValue;
2639 fastPathCheckNeeded = true;
2640 }
2641
2642 /**
2643 * Allows you to get the behavior of the decimal separator with integers.
2644 * (The decimal separator will always appear with decimals.)
2645 * <P>Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345
2646 *
2647 * @return {@code true} if the decimal separator is always shown;
2648 * {@code false} otherwise
2649 */
2650 public boolean isDecimalSeparatorAlwaysShown() {
2651 return decimalSeparatorAlwaysShown;
2652 }
2653
2654 /**
2655 * Allows you to set the behavior of the decimal separator with integers.
2656 * (The decimal separator will always appear with decimals.)
2657 * <P>Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345
2658 *
2659 * @param newValue {@code true} if the decimal separator is always shown;
2660 * {@code false} otherwise
2661 */
2662 public void setDecimalSeparatorAlwaysShown(boolean newValue) {
2663 decimalSeparatorAlwaysShown = newValue;
2664 fastPathCheckNeeded = true;
2665 }
2666
2667 /**
2668 * Returns whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
2669 * method returns <code>BigDecimal</code>. The default value is false.
2670 *
2671 * @return {@code true} if the parse method returns BigDecimal;
2672 * {@code false} otherwise
2673 * @see #setParseBigDecimal
2674 * @since 1.5
2675 */
2676 public boolean isParseBigDecimal() {
2677 return parseBigDecimal;
2678 }
2679
2680 /**
2681 * Sets whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
2682 * method returns <code>BigDecimal</code>.
2683 *
2684 * @param newValue {@code true} if the parse method returns BigDecimal;
2685 * {@code false} otherwise
2686 * @see #isParseBigDecimal
2687 * @since 1.5
2688 */
2689 public void setParseBigDecimal(boolean newValue) {
2690 parseBigDecimal = newValue;
2691 }
2692
2693 /**
2694 * Standard override; no change in semantics.
2695 */
2696 @Override
2697 public Object clone() {
2698 DecimalFormat other = (DecimalFormat) super.clone();
2699 other.symbols = (DecimalFormatSymbols) symbols.clone();
2700 other.digitList = (DigitList) digitList.clone();
2701
2702 // Fast-path is almost stateless algorithm. The only logical state is the
2703 // isFastPath flag. In addition fastPathCheckNeeded is a sentinel flag
2704 // that forces recalculation of all fast-path fields when set to true.
2705 //
2706 // There is thus no need to clone all the fast-path fields.
2707 // We just only need to set fastPathCheckNeeded to true when cloning,
2708 // and init fastPathData to null as if it were a truly new instance.
2709 // Every fast-path field will be recalculated (only once) at next usage of
2710 // fast-path algorithm.
2711 other.fastPathCheckNeeded = true;
2712 other.isFastPath = false;
2713 other.fastPathData = null;
2714
2715 return other;
2716 }
2717
2718 /**
2719 * Overrides equals
2720 */
2721 @Override
2722 public boolean equals(Object obj)
2723 {
2724 if (obj == null)
2725 return false;
2726 if (!super.equals(obj))
2727 return false; // super does class check
2728 DecimalFormat other = (DecimalFormat) obj;
2729 return ((posPrefixPattern == other.posPrefixPattern &&
2730 positivePrefix.equals(other.positivePrefix))
2731 || (posPrefixPattern != null &&
2732 posPrefixPattern.equals(other.posPrefixPattern)))
2733 && ((posSuffixPattern == other.posSuffixPattern &&
2734 positiveSuffix.equals(other.positiveSuffix))
2735 || (posSuffixPattern != null &&
2736 posSuffixPattern.equals(other.posSuffixPattern)))
2737 && ((negPrefixPattern == other.negPrefixPattern &&
2738 negativePrefix.equals(other.negativePrefix))
2739 || (negPrefixPattern != null &&
2740 negPrefixPattern.equals(other.negPrefixPattern)))
2741 && ((negSuffixPattern == other.negSuffixPattern &&
2742 negativeSuffix.equals(other.negativeSuffix))
2743 || (negSuffixPattern != null &&
2744 negSuffixPattern.equals(other.negSuffixPattern)))
2745 && multiplier == other.multiplier
2746 && groupingSize == other.groupingSize
2747 && decimalSeparatorAlwaysShown == other.decimalSeparatorAlwaysShown
2748 && parseBigDecimal == other.parseBigDecimal
2749 && useExponentialNotation == other.useExponentialNotation
2750 && (!useExponentialNotation ||
2751 minExponentDigits == other.minExponentDigits)
2752 && maximumIntegerDigits == other.maximumIntegerDigits
2753 && minimumIntegerDigits == other.minimumIntegerDigits
2754 && maximumFractionDigits == other.maximumFractionDigits
2755 && minimumFractionDigits == other.minimumFractionDigits
2756 && roundingMode == other.roundingMode
2757 && symbols.equals(other.symbols);
2758 }
2759
2760 /**
2761 * Overrides hashCode
2762 */
2763 @Override
2764 public int hashCode() {
2765 return super.hashCode() * 37 + positivePrefix.hashCode();
2766 // just enough fields for a reasonable distribution
2767 }
2768
2769 /**
2770 * Synthesizes a pattern string that represents the current state
2771 * of this Format object.
2772 *
2773 * @return a pattern string
2774 * @see #applyPattern
2775 */
2776 public String toPattern() {
2777 return toPattern( false );
2778 }
2779
2780 /**
2781 * Synthesizes a localized pattern string that represents the current
2782 * state of this Format object.
2783 *
2784 * @return a localized pattern string
2785 * @see #applyPattern
2786 */
2787 public String toLocalizedPattern() {
2788 return toPattern( true );
2789 }
2790
2791 /**
2792 * Expand the affix pattern strings into the expanded affix strings. If any
2793 * affix pattern string is null, do not expand it. This method should be
2794 * called any time the symbols or the affix patterns change in order to keep
2795 * the expanded affix strings up to date.
2796 */
2797 private void expandAffixes() {
2798 // Reuse one StringBuffer for better performance
2799 StringBuffer buffer = new StringBuffer();
2800 if (posPrefixPattern != null) {
2801 positivePrefix = expandAffix(posPrefixPattern, buffer);
2802 positivePrefixFieldPositions = null;
2803 }
2804 if (posSuffixPattern != null) {
2805 positiveSuffix = expandAffix(posSuffixPattern, buffer);
2806 positiveSuffixFieldPositions = null;
2807 }
2808 if (negPrefixPattern != null) {
2809 negativePrefix = expandAffix(negPrefixPattern, buffer);
2810 negativePrefixFieldPositions = null;
2811 }
2812 if (negSuffixPattern != null) {
2813 negativeSuffix = expandAffix(negSuffixPattern, buffer);
2814 negativeSuffixFieldPositions = null;
2815 }
2816 }
2817
2818 /**
2819 * Expand an affix pattern into an affix string. All characters in the
2820 * pattern are literal unless prefixed by QUOTE. The following characters
2821 * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
2822 * PATTERN_MINUS, and CURRENCY_SIGN. If CURRENCY_SIGN is doubled (QUOTE +
2823 * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
2824 * currency code. Any other character after a QUOTE represents itself.
2825 * QUOTE must be followed by another character; QUOTE may not occur by
2826 * itself at the end of the pattern.
2827 *
2828 * @param pattern the non-null, possibly empty pattern
2829 * @param buffer a scratch StringBuffer; its contents will be lost
2830 * @return the expanded equivalent of pattern
2831 */
2832 private String expandAffix(String pattern, StringBuffer buffer) {
2833 buffer.setLength(0);
2834 for (int i=0; i<pattern.length(); ) {
2835 char c = pattern.charAt(i++);
2836 if (c == QUOTE) {
2837 c = pattern.charAt(i++);
2838 switch (c) {
2839 case CURRENCY_SIGN:
2840 if (i<pattern.length() &&
2841 pattern.charAt(i) == CURRENCY_SIGN) {
2842 ++i;
2843 buffer.append(symbols.getInternationalCurrencySymbol());
2844 } else {
2845 buffer.append(symbols.getCurrencySymbol());
2846 }
2847 continue;
2848 case PATTERN_PERCENT:
2849 c = symbols.getPercent();
2850 break;
2851 case PATTERN_PER_MILLE:
2852 c = symbols.getPerMill();
2853 break;
2854 case PATTERN_MINUS:
2855 c = symbols.getMinusSign();
2856 break;
2857 }
2858 }
2859 buffer.append(c);
2860 }
2861 return buffer.toString();
2862 }
2863
2864 /**
2865 * Expand an affix pattern into an array of FieldPositions describing
2866 * how the pattern would be expanded.
2867 * All characters in the
2868 * pattern are literal unless prefixed by QUOTE. The following characters
2869 * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
2870 * PATTERN_MINUS, and CURRENCY_SIGN. If CURRENCY_SIGN is doubled (QUOTE +
2871 * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
2872 * currency code. Any other character after a QUOTE represents itself.
2873 * QUOTE must be followed by another character; QUOTE may not occur by
2874 * itself at the end of the pattern.
2875 *
2876 * @param pattern the non-null, possibly empty pattern
2877 * @return FieldPosition array of the resulting fields.
2878 */
2879 private FieldPosition[] expandAffix(String pattern) {
2880 ArrayList<FieldPosition> positions = null;
2881 int stringIndex = 0;
2882 for (int i=0; i<pattern.length(); ) {
2883 char c = pattern.charAt(i++);
2884 if (c == QUOTE) {
2885 int field = -1;
2886 Format.Field fieldID = null;
2887 c = pattern.charAt(i++);
2888 switch (c) {
2889 case CURRENCY_SIGN:
2890 String string;
2891 if (i<pattern.length() &&
2892 pattern.charAt(i) == CURRENCY_SIGN) {
2893 ++i;
2894 string = symbols.getInternationalCurrencySymbol();
2895 } else {
2896 string = symbols.getCurrencySymbol();
2897 }
2898 if (string.length() > 0) {
2899 if (positions == null) {
2900 positions = new ArrayList<>(2);
2901 }
2902 FieldPosition fp = new FieldPosition(Field.CURRENCY);
2903 fp.setBeginIndex(stringIndex);
2904 fp.setEndIndex(stringIndex + string.length());
2905 positions.add(fp);
2906 stringIndex += string.length();
2907 }
2908 continue;
2909 case PATTERN_PERCENT:
2910 c = symbols.getPercent();
2911 field = -1;
2912 fieldID = Field.PERCENT;
2913 break;
2914 case PATTERN_PER_MILLE:
2915 c = symbols.getPerMill();
2916 field = -1;
2917 fieldID = Field.PERMILLE;
2918 break;
2919 case PATTERN_MINUS:
2920 c = symbols.getMinusSign();
2921 field = -1;
2922 fieldID = Field.SIGN;
2923 break;
2924 }
2925 if (fieldID != null) {
2926 if (positions == null) {
2927 positions = new ArrayList<>(2);
2928 }
2929 FieldPosition fp = new FieldPosition(fieldID, field);
2930 fp.setBeginIndex(stringIndex);
2931 fp.setEndIndex(stringIndex + 1);
2932 positions.add(fp);
2933 }
2934 }
2935 stringIndex++;
2936 }
2937 if (positions != null) {
2938 return positions.toArray(EmptyFieldPositionArray);
2939 }
2940 return EmptyFieldPositionArray;
2941 }
2942
2943 /**
2944 * Appends an affix pattern to the given StringBuffer, quoting special
2945 * characters as needed. Uses the internal affix pattern, if that exists,
2946 * or the literal affix, if the internal affix pattern is null. The
2947 * appended string will generate the same affix pattern (or literal affix)
2948 * when passed to toPattern().
2949 *
2950 * @param buffer the affix string is appended to this
2951 * @param affixPattern a pattern such as posPrefixPattern; may be null
2952 * @param expAffix a corresponding expanded affix, such as positivePrefix.
2953 * Ignored unless affixPattern is null. If affixPattern is null, then
2954 * expAffix is appended as a literal affix.
2955 * @param localized true if the appended pattern should contain localized
2956 * pattern characters; otherwise, non-localized pattern chars are appended
2957 */
2958 private void appendAffix(StringBuffer buffer, String affixPattern,
2959 String expAffix, boolean localized) {
2960 if (affixPattern == null) {
2961 appendAffix(buffer, expAffix, localized);
2962 } else {
2963 int i;
2964 for (int pos=0; pos<affixPattern.length(); pos=i) {
2965 i = affixPattern.indexOf(QUOTE, pos);
2966 if (i < 0) {
2967 appendAffix(buffer, affixPattern.substring(pos), localized);
2968 break;
2969 }
2970 if (i > pos) {
2971 appendAffix(buffer, affixPattern.substring(pos, i), localized);
2972 }
2973 char c = affixPattern.charAt(++i);
2974 ++i;
2975 if (c == QUOTE) {
2976 buffer.append(c);
2977 // Fall through and append another QUOTE below
2978 } else if (c == CURRENCY_SIGN &&
2979 i<affixPattern.length() &&
2980 affixPattern.charAt(i) == CURRENCY_SIGN) {
2981 ++i;
2982 buffer.append(c);
2983 // Fall through and append another CURRENCY_SIGN below
2984 } else if (localized) {
2985 switch (c) {
2986 case PATTERN_PERCENT:
2987 c = symbols.getPercent();
2988 break;
2989 case PATTERN_PER_MILLE:
2990 c = symbols.getPerMill();
2991 break;
2992 case PATTERN_MINUS:
2993 c = symbols.getMinusSign();
2994 break;
2995 }
2996 }
2997 buffer.append(c);
2998 }
2999 }
3000 }
3001
3002 /**
3003 * Append an affix to the given StringBuffer, using quotes if
3004 * there are special characters. Single quotes themselves must be
3005 * escaped in either case.
3006 */
3007 private void appendAffix(StringBuffer buffer, String affix, boolean localized) {
3008 boolean needQuote;
3009 if (localized) {
3010 needQuote = affix.indexOf(symbols.getZeroDigit()) >= 0
3011 || affix.indexOf(symbols.getGroupingSeparator()) >= 0
3012 || affix.indexOf(symbols.getDecimalSeparator()) >= 0
3013 || affix.indexOf(symbols.getPercent()) >= 0
3014 || affix.indexOf(symbols.getPerMill()) >= 0
3015 || affix.indexOf(symbols.getDigit()) >= 0
3016 || affix.indexOf(symbols.getPatternSeparator()) >= 0
3017 || affix.indexOf(symbols.getMinusSign()) >= 0
3018 || affix.indexOf(CURRENCY_SIGN) >= 0;
3019 } else {
3020 needQuote = affix.indexOf(PATTERN_ZERO_DIGIT) >= 0
3021 || affix.indexOf(PATTERN_GROUPING_SEPARATOR) >= 0
3022 || affix.indexOf(PATTERN_DECIMAL_SEPARATOR) >= 0
3023 || affix.indexOf(PATTERN_PERCENT) >= 0
3024 || affix.indexOf(PATTERN_PER_MILLE) >= 0
3025 || affix.indexOf(PATTERN_DIGIT) >= 0
3026 || affix.indexOf(PATTERN_SEPARATOR) >= 0
3027 || affix.indexOf(PATTERN_MINUS) >= 0
3028 || affix.indexOf(CURRENCY_SIGN) >= 0;
3029 }
3030 if (needQuote) buffer.append('\'');
3031 if (affix.indexOf('\'') < 0) buffer.append(affix);
3032 else {
3033 for (int j=0; j<affix.length(); ++j) {
3034 char c = affix.charAt(j);
3035 buffer.append(c);
3036 if (c == '\'') buffer.append(c);
3037 }
3038 }
3039 if (needQuote) buffer.append('\'');
3040 }
3041
3042 /**
3043 * Does the real work of generating a pattern. */
3044 private String toPattern(boolean localized) {
3045 StringBuffer result = new StringBuffer();
3046 for (int j = 1; j >= 0; --j) {
3047 if (j == 1)
3048 appendAffix(result, posPrefixPattern, positivePrefix, localized);
3049 else appendAffix(result, negPrefixPattern, negativePrefix, localized);
3050 int i;
3051 int digitCount = useExponentialNotation
3052 ? getMaximumIntegerDigits()
3053 : Math.max(groupingSize, getMinimumIntegerDigits())+1;
3054 for (i = digitCount; i > 0; --i) {
3055 if (i != digitCount && isGroupingUsed() && groupingSize != 0 &&
3056 i % groupingSize == 0) {
3057 result.append(localized ? symbols.getGroupingSeparator() :
3058 PATTERN_GROUPING_SEPARATOR);
3059 }
3060 result.append(i <= getMinimumIntegerDigits()
3061 ? (localized ? symbols.getZeroDigit() : PATTERN_ZERO_DIGIT)
3062 : (localized ? symbols.getDigit() : PATTERN_DIGIT));
3063 }
3064 if (getMaximumFractionDigits() > 0 || decimalSeparatorAlwaysShown)
3065 result.append(localized ? symbols.getDecimalSeparator() :
3066 PATTERN_DECIMAL_SEPARATOR);
3067 for (i = 0; i < getMaximumFractionDigits(); ++i) {
3068 if (i < getMinimumFractionDigits()) {
3069 result.append(localized ? symbols.getZeroDigit() :
3070 PATTERN_ZERO_DIGIT);
3071 } else {
3072 result.append(localized ? symbols.getDigit() :
3073 PATTERN_DIGIT);
3074 }
3075 }
3076 if (useExponentialNotation)
3077 {
3078 result.append(localized ? symbols.getExponentSeparator() :
3079 PATTERN_EXPONENT);
3080 for (i=0; i<minExponentDigits; ++i)
3081 result.append(localized ? symbols.getZeroDigit() :
3082 PATTERN_ZERO_DIGIT);
3083 }
3084 if (j == 1) {
3085 appendAffix(result, posSuffixPattern, positiveSuffix, localized);
3086 if ((negSuffixPattern == posSuffixPattern && // n == p == null
3087 negativeSuffix.equals(positiveSuffix))
3088 || (negSuffixPattern != null &&
3089 negSuffixPattern.equals(posSuffixPattern))) {
3090 if ((negPrefixPattern != null && posPrefixPattern != null &&
3091 negPrefixPattern.equals("'-" + posPrefixPattern)) ||
3092 (negPrefixPattern == posPrefixPattern && // n == p == null
3093 negativePrefix.equals(symbols.getMinusSign() + positivePrefix)))
3094 break;
3095 }
3096 result.append(localized ? symbols.getPatternSeparator() :
3097 PATTERN_SEPARATOR);
3098 } else appendAffix(result, negSuffixPattern, negativeSuffix, localized);
3099 }
3100 return result.toString();
3101 }
3102
3103 /**
3104 * Apply the given pattern to this Format object. A pattern is a
3105 * short-hand specification for the various formatting properties.
3106 * These properties can also be changed individually through the
3107 * various setter methods.
3108 * <p>
3109 * There is no limit to integer digits set
3110 * by this routine, since that is the typical end-user desire;
3111 * use setMaximumInteger if you want to set a real value.
3112 * For negative numbers, use a second pattern, separated by a semicolon
3113 * <P>Example <code>"#,#00.0#"</code> → 1,234.56
3114 * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
3115 * a maximum of 2 fraction digits.
3116 * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
3117 * parentheses.
3118 * <p>In negative patterns, the minimum and maximum counts are ignored;
3119 * these are presumed to be set in the positive pattern.
3120 *
3121 * @param pattern a new pattern
3122 * @exception NullPointerException if <code>pattern</code> is null
3123 * @exception IllegalArgumentException if the given pattern is invalid.
3124 */
3125 public void applyPattern(String pattern) {
3126 applyPattern(pattern, false);
3127 }
3128
3129 /**
3130 * Apply the given pattern to this Format object. The pattern
3131 * is assumed to be in a localized notation. A pattern is a
3132 * short-hand specification for the various formatting properties.
3133 * These properties can also be changed individually through the
3134 * various setter methods.
3135 * <p>
3136 * There is no limit to integer digits set
3137 * by this routine, since that is the typical end-user desire;
3138 * use setMaximumInteger if you want to set a real value.
3139 * For negative numbers, use a second pattern, separated by a semicolon
3140 * <P>Example <code>"#,#00.0#"</code> → 1,234.56
3141 * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
3142 * a maximum of 2 fraction digits.
3143 * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
3144 * parentheses.
3145 * <p>In negative patterns, the minimum and maximum counts are ignored;
3146 * these are presumed to be set in the positive pattern.
3147 *
3148 * @param pattern a new pattern
3149 * @exception NullPointerException if <code>pattern</code> is null
3150 * @exception IllegalArgumentException if the given pattern is invalid.
3151 */
3152 public void applyLocalizedPattern(String pattern) {
3153 applyPattern(pattern, true);
3154 }
3155
3156 /**
3157 * Does the real work of applying a pattern.
3158 */
3159 private void applyPattern(String pattern, boolean localized) {
3160 char zeroDigit = PATTERN_ZERO_DIGIT;
3161 char groupingSeparator = PATTERN_GROUPING_SEPARATOR;
3162 char decimalSeparator = PATTERN_DECIMAL_SEPARATOR;
3163 char percent = PATTERN_PERCENT;
3164 char perMill = PATTERN_PER_MILLE;
3165 char digit = PATTERN_DIGIT;
3166 char separator = PATTERN_SEPARATOR;
3167 String exponent = PATTERN_EXPONENT;
3168 char minus = PATTERN_MINUS;
3169 if (localized) {
3170 zeroDigit = symbols.getZeroDigit();
3171 groupingSeparator = symbols.getGroupingSeparator();
3172 decimalSeparator = symbols.getDecimalSeparator();
3173 percent = symbols.getPercent();
3174 perMill = symbols.getPerMill();
3175 digit = symbols.getDigit();
3176 separator = symbols.getPatternSeparator();
3177 exponent = symbols.getExponentSeparator();
3178 minus = symbols.getMinusSign();
3179 }
3180 boolean gotNegative = false;
3181 decimalSeparatorAlwaysShown = false;
3182 isCurrencyFormat = false;
3183 useExponentialNotation = false;
3184
3185 // Two variables are used to record the subrange of the pattern
3186 // occupied by phase 1. This is used during the processing of the
3187 // second pattern (the one representing negative numbers) to ensure
3188 // that no deviation exists in phase 1 between the two patterns.
3189 int phaseOneStart = 0;
3190 int phaseOneLength = 0;
3191
3192 int start = 0;
3193 for (int j = 1; j >= 0 && start < pattern.length(); --j) {
3194 boolean inQuote = false;
3195 StringBuffer prefix = new StringBuffer();
3196 StringBuffer suffix = new StringBuffer();
3197 int decimalPos = -1;
3198 int multiplier = 1;
3199 int digitLeftCount = 0, zeroDigitCount = 0, digitRightCount = 0;
3200 byte groupingCount = -1;
3201
3202 // The phase ranges from 0 to 2. Phase 0 is the prefix. Phase 1 is
3203 // the section of the pattern with digits, decimal separator,
3204 // grouping characters. Phase 2 is the suffix. In phases 0 and 2,
3205 // percent, per mille, and currency symbols are recognized and
3206 // translated. The separation of the characters into phases is
3207 // strictly enforced; if phase 1 characters are to appear in the
3208 // suffix, for example, they must be quoted.
3209 int phase = 0;
3210
3211 // The affix is either the prefix or the suffix.
3212 StringBuffer affix = prefix;
3213
3214 for (int pos = start; pos < pattern.length(); ++pos) {
3215 char ch = pattern.charAt(pos);
3216 switch (phase) {
3217 case 0:
3218 case 2:
3219 // Process the prefix / suffix characters
3220 if (inQuote) {
3221 // A quote within quotes indicates either the closing
3222 // quote or two quotes, which is a quote literal. That
3223 // is, we have the second quote in 'do' or 'don''t'.
3224 if (ch == QUOTE) {
3225 if ((pos+1) < pattern.length() &&
3226 pattern.charAt(pos+1) == QUOTE) {
3227 ++pos;
3228 affix.append("''"); // 'don''t'
3229 } else {
3230 inQuote = false; // 'do'
3231 }
3232 continue;
3233 }
3234 } else {
3235 // Process unquoted characters seen in prefix or suffix
3236 // phase.
3237 if (ch == digit ||
3238 ch == zeroDigit ||
3239 ch == groupingSeparator ||
3240 ch == decimalSeparator) {
3241 phase = 1;
3242 if (j == 1) {
3243 phaseOneStart = pos;
3244 }
3245 --pos; // Reprocess this character
3246 continue;
3247 } else if (ch == CURRENCY_SIGN) {
3248 // Use lookahead to determine if the currency sign
3249 // is doubled or not.
3250 boolean doubled = (pos + 1) < pattern.length() &&
3251 pattern.charAt(pos + 1) == CURRENCY_SIGN;
3252 if (doubled) { // Skip over the doubled character
3253 ++pos;
3254 }
3255 isCurrencyFormat = true;
3256 affix.append(doubled ? "'\u00A4\u00A4" : "'\u00A4");
3257 continue;
3258 } else if (ch == QUOTE) {
3259 // A quote outside quotes indicates either the
3260 // opening quote or two quotes, which is a quote
3261 // literal. That is, we have the first quote in 'do'
3262 // or o''clock.
3263 if (ch == QUOTE) {
3264 if ((pos+1) < pattern.length() &&
3265 pattern.charAt(pos+1) == QUOTE) {
3266 ++pos;
3267 affix.append("''"); // o''clock
3268 } else {
3269 inQuote = true; // 'do'
3270 }
3271 continue;
3272 }
3273 } else if (ch == separator) {
3274 // Don't allow separators before we see digit
3275 // characters of phase 1, and don't allow separators
3276 // in the second pattern (j == 0).
3277 if (phase == 0 || j == 0) {
3278 throw new IllegalArgumentException("Unquoted special character '" +
3279 ch + "' in pattern \"" + pattern + '"');
3280 }
3281 start = pos + 1;
3282 pos = pattern.length();
3283 continue;
3284 }
3285
3286 // Next handle characters which are appended directly.
3287 else if (ch == percent) {
3288 if (multiplier != 1) {
3289 throw new IllegalArgumentException("Too many percent/per mille characters in pattern \"" +
3290 pattern + '"');
3291 }
3292 multiplier = 100;
3293 affix.append("'%");
3294 continue;
3295 } else if (ch == perMill) {
3296 if (multiplier != 1) {
3297 throw new IllegalArgumentException("Too many percent/per mille characters in pattern \"" +
3298 pattern + '"');
3299 }
3300 multiplier = 1000;
3301 affix.append("'\u2030");
3302 continue;
3303 } else if (ch == minus) {
3304 affix.append("'-");
3305 continue;
3306 }
3307 }
3308 // Note that if we are within quotes, or if this is an
3309 // unquoted, non-special character, then we usually fall
3310 // through to here.
3311 affix.append(ch);
3312 break;
3313
3314 case 1:
3315 // Phase one must be identical in the two sub-patterns. We
3316 // enforce this by doing a direct comparison. While
3317 // processing the first sub-pattern, we just record its
3318 // length. While processing the second, we compare
3319 // characters.
3320 if (j == 1) {
3321 ++phaseOneLength;
3322 } else {
3323 if (--phaseOneLength == 0) {
3324 phase = 2;
3325 affix = suffix;
3326 }
3327 continue;
3328 }
3329
3330 // Process the digits, decimal, and grouping characters. We
3331 // record five pieces of information. We expect the digits
3332 // to occur in the pattern ####0000.####, and we record the
3333 // number of left digits, zero (central) digits, and right
3334 // digits. The position of the last grouping character is
3335 // recorded (should be somewhere within the first two blocks
3336 // of characters), as is the position of the decimal point,
3337 // if any (should be in the zero digits). If there is no
3338 // decimal point, then there should be no right digits.
3339 if (ch == digit) {
3340 if (zeroDigitCount > 0) {
3341 ++digitRightCount;
3342 } else {
3343 ++digitLeftCount;
3344 }
3345 if (groupingCount >= 0 && decimalPos < 0) {
3346 ++groupingCount;
3347 }
3348 } else if (ch == zeroDigit) {
3349 if (digitRightCount > 0) {
3350 throw new IllegalArgumentException("Unexpected '0' in pattern \"" +
3351 pattern + '"');
3352 }
3353 ++zeroDigitCount;
3354 if (groupingCount >= 0 && decimalPos < 0) {
3355 ++groupingCount;
3356 }
3357 } else if (ch == groupingSeparator) {
3358 groupingCount = 0;
3359 } else if (ch == decimalSeparator) {
3360 if (decimalPos >= 0) {
3361 throw new IllegalArgumentException("Multiple decimal separators in pattern \"" +
3362 pattern + '"');
3363 }
3364 decimalPos = digitLeftCount + zeroDigitCount + digitRightCount;
3365 } else if (pattern.regionMatches(pos, exponent, 0, exponent.length())){
3366 if (useExponentialNotation) {
3367 throw new IllegalArgumentException("Multiple exponential " +
3368 "symbols in pattern \"" + pattern + '"');
3369 }
3370 useExponentialNotation = true;
3371 minExponentDigits = 0;
3372
3373 // Use lookahead to parse out the exponential part
3374 // of the pattern, then jump into phase 2.
3375 pos = pos+exponent.length();
3376 while (pos < pattern.length() &&
3377 pattern.charAt(pos) == zeroDigit) {
3378 ++minExponentDigits;
3379 ++phaseOneLength;
3380 ++pos;
3381 }
3382
3383 if ((digitLeftCount + zeroDigitCount) < 1 ||
3384 minExponentDigits < 1) {
3385 throw new IllegalArgumentException("Malformed exponential " +
3386 "pattern \"" + pattern + '"');
3387 }
3388
3389 // Transition to phase 2
3390 phase = 2;
3391 affix = suffix;
3392 --pos;
3393 continue;
3394 } else {
3395 phase = 2;
3396 affix = suffix;
3397 --pos;
3398 --phaseOneLength;
3399 continue;
3400 }
3401 break;
3402 }
3403 }
3404
3405 // Handle patterns with no '0' pattern character. These patterns
3406 // are legal, but must be interpreted. "##.###" -> "#0.###".
3407 // ".###" -> ".0##".
3408 /* We allow patterns of the form "####" to produce a zeroDigitCount
3409 * of zero (got that?); although this seems like it might make it
3410 * possible for format() to produce empty strings, format() checks
3411 * for this condition and outputs a zero digit in this situation.
3412 * Having a zeroDigitCount of zero yields a minimum integer digits
3413 * of zero, which allows proper round-trip patterns. That is, we
3414 * don't want "#" to become "#0" when toPattern() is called (even
3415 * though that's what it really is, semantically).
3416 */
3417 if (zeroDigitCount == 0 && digitLeftCount > 0 && decimalPos >= 0) {
3418 // Handle "###.###" and "###." and ".###"
3419 int n = decimalPos;
3420 if (n == 0) { // Handle ".###"
3421 ++n;
3422 }
3423 digitRightCount = digitLeftCount - n;
3424 digitLeftCount = n - 1;
3425 zeroDigitCount = 1;
3426 }
3427
3428 // Do syntax checking on the digits.
3429 if ((decimalPos < 0 && digitRightCount > 0) ||
3430 (decimalPos >= 0 && (decimalPos < digitLeftCount ||
3431 decimalPos > (digitLeftCount + zeroDigitCount))) ||
3432 groupingCount == 0 || inQuote) {
3433 throw new IllegalArgumentException("Malformed pattern \"" +
3434 pattern + '"');
3435 }
3436
3437 if (j == 1) {
3438 posPrefixPattern = prefix.toString();
3439 posSuffixPattern = suffix.toString();
3440 negPrefixPattern = posPrefixPattern; // assume these for now
3441 negSuffixPattern = posSuffixPattern;
3442 int digitTotalCount = digitLeftCount + zeroDigitCount + digitRightCount;
3443 /* The effectiveDecimalPos is the position the decimal is at or
3444 * would be at if there is no decimal. Note that if decimalPos<0,
3445 * then digitTotalCount == digitLeftCount + zeroDigitCount.
3446 */
3447 int effectiveDecimalPos = decimalPos >= 0 ?
3448 decimalPos : digitTotalCount;
3449 setMinimumIntegerDigits(effectiveDecimalPos - digitLeftCount);
3450 setMaximumIntegerDigits(useExponentialNotation ?
3451 digitLeftCount + getMinimumIntegerDigits() :
3452 MAXIMUM_INTEGER_DIGITS);
3453 setMaximumFractionDigits(decimalPos >= 0 ?
3454 (digitTotalCount - decimalPos) : 0);
3455 setMinimumFractionDigits(decimalPos >= 0 ?
3456 (digitLeftCount + zeroDigitCount - decimalPos) : 0);
3457 setGroupingUsed(groupingCount > 0);
3458 this.groupingSize = (groupingCount > 0) ? groupingCount : 0;
3459 this.multiplier = multiplier;
3460 setDecimalSeparatorAlwaysShown(decimalPos == 0 ||
3461 decimalPos == digitTotalCount);
3462 } else {
3463 negPrefixPattern = prefix.toString();
3464 negSuffixPattern = suffix.toString();
3465 gotNegative = true;
3466 }
3467 }
3468
3469 if (pattern.length() == 0) {
3470 posPrefixPattern = posSuffixPattern = "";
3471 setMinimumIntegerDigits(0);
3472 setMaximumIntegerDigits(MAXIMUM_INTEGER_DIGITS);
3473 setMinimumFractionDigits(0);
3474 setMaximumFractionDigits(MAXIMUM_FRACTION_DIGITS);
3475 }
3476
3477 // If there was no negative pattern, or if the negative pattern is
3478 // identical to the positive pattern, then prepend the minus sign to
3479 // the positive pattern to form the negative pattern.
3480 if (!gotNegative ||
3481 (negPrefixPattern.equals(posPrefixPattern)
3482 && negSuffixPattern.equals(posSuffixPattern))) {
3483 negSuffixPattern = posSuffixPattern;
3484 negPrefixPattern = "'-" + posPrefixPattern;
3485 }
3486
3487 expandAffixes();
3488 }
3489
3490 /**
3491 * Sets the maximum number of digits allowed in the integer portion of a
3492 * number.
3493 * For formatting numbers other than <code>BigInteger</code> and
3494 * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3495 * 309 is used. Negative input values are replaced with 0.
3496 * @see NumberFormat#setMaximumIntegerDigits
3497 */
3498 @Override
3499 public void setMaximumIntegerDigits(int newValue) {
3500 maximumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
3501 super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3502 DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
3503 if (minimumIntegerDigits > maximumIntegerDigits) {
3504 minimumIntegerDigits = maximumIntegerDigits;
3505 super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3506 DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
3507 }
3508 fastPathCheckNeeded = true;
3509 }
3510
3511 /**
3512 * Sets the minimum number of digits allowed in the integer portion of a
3513 * number.
3514 * For formatting numbers other than <code>BigInteger</code> and
3515 * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3516 * 309 is used. Negative input values are replaced with 0.
3517 * @see NumberFormat#setMinimumIntegerDigits
3518 */
3519 @Override
3520 public void setMinimumIntegerDigits(int newValue) {
3521 minimumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
3522 super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3523 DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
3524 if (minimumIntegerDigits > maximumIntegerDigits) {
3525 maximumIntegerDigits = minimumIntegerDigits;
3526 super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3527 DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
3528 }
3529 fastPathCheckNeeded = true;
3530 }
3531
3532 /**
3533 * Sets the maximum number of digits allowed in the fraction portion of a
3534 * number.
3535 * For formatting numbers other than <code>BigInteger</code> and
3536 * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3537 * 340 is used. Negative input values are replaced with 0.
3538 * @see NumberFormat#setMaximumFractionDigits
3539 */
3540 @Override
3541 public void setMaximumFractionDigits(int newValue) {
3542 maximumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
3543 super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3544 DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
3545 if (minimumFractionDigits > maximumFractionDigits) {
3546 minimumFractionDigits = maximumFractionDigits;
3547 super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3548 DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
3549 }
3550 fastPathCheckNeeded = true;
3551 }
3552
3553 /**
3554 * Sets the minimum number of digits allowed in the fraction portion of a
3555 * number.
3556 * For formatting numbers other than <code>BigInteger</code> and
3557 * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3558 * 340 is used. Negative input values are replaced with 0.
3559 * @see NumberFormat#setMinimumFractionDigits
3560 */
3561 @Override
3562 public void setMinimumFractionDigits(int newValue) {
3563 minimumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
3564 super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3565 DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
3566 if (minimumFractionDigits > maximumFractionDigits) {
3567 maximumFractionDigits = minimumFractionDigits;
3568 super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3569 DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
3570 }
3571 fastPathCheckNeeded = true;
3572 }
3573
3574 /**
3575 * Gets the maximum number of digits allowed in the integer portion of a
3576 * number.
3577 * For formatting numbers other than <code>BigInteger</code> and
3578 * <code>BigDecimal</code> objects, the lower of the return value and
3579 * 309 is used.
3580 * @see #setMaximumIntegerDigits
3581 */
3582 @Override
3583 public int getMaximumIntegerDigits() {
3584 return maximumIntegerDigits;
3585 }
3586
3587 /**
3588 * Gets the minimum number of digits allowed in the integer portion of a
3589 * number.
3590 * For formatting numbers other than <code>BigInteger</code> and
3591 * <code>BigDecimal</code> objects, the lower of the return value and
3592 * 309 is used.
3593 * @see #setMinimumIntegerDigits
3594 */
3595 @Override
3596 public int getMinimumIntegerDigits() {
3597 return minimumIntegerDigits;
3598 }
3599
3600 /**
3601 * Gets the maximum number of digits allowed in the fraction portion of a
3602 * number.
3603 * For formatting numbers other than <code>BigInteger</code> and
3604 * <code>BigDecimal</code> objects, the lower of the return value and
3605 * 340 is used.
3606 * @see #setMaximumFractionDigits
3607 */
3608 @Override
3609 public int getMaximumFractionDigits() {
3610 return maximumFractionDigits;
3611 }
3612
3613 /**
3614 * Gets the minimum number of digits allowed in the fraction portion of a
3615 * number.
3616 * For formatting numbers other than <code>BigInteger</code> and
3617 * <code>BigDecimal</code> objects, the lower of the return value and
3618 * 340 is used.
3619 * @see #setMinimumFractionDigits
3620 */
3621 @Override
3622 public int getMinimumFractionDigits() {
3623 return minimumFractionDigits;
3624 }
3625
3626 /**
3627 * Gets the currency used by this decimal format when formatting
3628 * currency values.
3629 * The currency is obtained by calling
3630 * {@link DecimalFormatSymbols#getCurrency DecimalFormatSymbols.getCurrency}
3631 * on this number format's symbols.
3632 *
3633 * @return the currency used by this decimal format, or <code>null</code>
3634 * @since 1.4
3635 */
3636 @Override
3637 public Currency getCurrency() {
3638 return symbols.getCurrency();
3639 }
3640
3641 /**
3642 * Sets the currency used by this number format when formatting
3643 * currency values. This does not update the minimum or maximum
3644 * number of fraction digits used by the number format.
3645 * The currency is set by calling
3646 * {@link DecimalFormatSymbols#setCurrency DecimalFormatSymbols.setCurrency}
3647 * on this number format's symbols.
3648 *
3649 * @param currency the new currency to be used by this decimal format
3650 * @exception NullPointerException if <code>currency</code> is null
3651 * @since 1.4
3652 */
3653 @Override
3654 public void setCurrency(Currency currency) {
3655 if (currency != symbols.getCurrency()) {
3656 symbols.setCurrency(currency);
3657 if (isCurrencyFormat) {
3658 expandAffixes();
3659 }
3660 }
3661 fastPathCheckNeeded = true;
3662 }
3663
3664 /**
3665 * Gets the {@link java.math.RoundingMode} used in this DecimalFormat.
3666 *
3667 * @return The <code>RoundingMode</code> used for this DecimalFormat.
3668 * @see #setRoundingMode(RoundingMode)
3669 * @since 1.6
3670 */
3671 @Override
3672 public RoundingMode getRoundingMode() {
3673 return roundingMode;
3674 }
3675
3676 /**
3677 * Sets the {@link java.math.RoundingMode} used in this DecimalFormat.
3678 *
3679 * @param roundingMode The <code>RoundingMode</code> to be used
3680 * @see #getRoundingMode()
3681 * @exception NullPointerException if <code>roundingMode</code> is null.
3682 * @since 1.6
3683 */
3684 @Override
3685 public void setRoundingMode(RoundingMode roundingMode) {
3686 if (roundingMode == null) {
3687 throw new NullPointerException();
3688 }
3689
3690 this.roundingMode = roundingMode;
3691 digitList.setRoundingMode(roundingMode);
3692 fastPathCheckNeeded = true;
3693 }
3694
3695 /**
3696 * Reads the default serializable fields from the stream and performs
3697 * validations and adjustments for older serialized versions. The
3698 * validations and adjustments are:
3699 * <ol>
3700 * <li>
3701 * Verify that the superclass's digit count fields correctly reflect
3702 * the limits imposed on formatting numbers other than
3703 * <code>BigInteger</code> and <code>BigDecimal</code> objects. These
3704 * limits are stored in the superclass for serialization compatibility
3705 * with older versions, while the limits for <code>BigInteger</code> and
3706 * <code>BigDecimal</code> objects are kept in this class.
3707 * If, in the superclass, the minimum or maximum integer digit count is
3708 * larger than <code>DOUBLE_INTEGER_DIGITS</code> or if the minimum or
3709 * maximum fraction digit count is larger than
3710 * <code>DOUBLE_FRACTION_DIGITS</code>, then the stream data is invalid
3711 * and this method throws an <code>InvalidObjectException</code>.
3712 * <li>
3713 * If <code>serialVersionOnStream</code> is less than 4, initialize
3714 * <code>roundingMode</code> to {@link java.math.RoundingMode#HALF_EVEN
3715 * RoundingMode.HALF_EVEN}. This field is new with version 4.
3716 * <li>
3717 * If <code>serialVersionOnStream</code> is less than 3, then call
3718 * the setters for the minimum and maximum integer and fraction digits with
3719 * the values of the corresponding superclass getters to initialize the
3720 * fields in this class. The fields in this class are new with version 3.
3721 * <li>
3722 * If <code>serialVersionOnStream</code> is less than 1, indicating that
3723 * the stream was written by JDK 1.1, initialize
3724 * <code>useExponentialNotation</code>
3725 * to false, since it was not present in JDK 1.1.
3726 * <li>
3727 * Set <code>serialVersionOnStream</code> to the maximum allowed value so
3728 * that default serialization will work properly if this object is streamed
3729 * out again.
3730 * </ol>
3731 *
3732 * <p>Stream versions older than 2 will not have the affix pattern variables
3733 * <code>posPrefixPattern</code> etc. As a result, they will be initialized
3734 * to <code>null</code>, which means the affix strings will be taken as
3735 * literal values. This is exactly what we want, since that corresponds to
3736 * the pre-version-2 behavior.
3737 */
3738 private void readObject(ObjectInputStream stream)
3739 throws IOException, ClassNotFoundException
3740 {
3741 stream.defaultReadObject();
3742 digitList = new DigitList();
3743
3744 // We force complete fast-path reinitialization when the instance is
3745 // deserialized. See clone() comment on fastPathCheckNeeded.
3746 fastPathCheckNeeded = true;
3747 isFastPath = false;
3748 fastPathData = null;
3749
3750 if (serialVersionOnStream < 4) {
3751 setRoundingMode(RoundingMode.HALF_EVEN);
3752 } else {
3753 setRoundingMode(getRoundingMode());
3754 }
3755
3756 // We only need to check the maximum counts because NumberFormat
3757 // .readObject has already ensured that the maximum is greater than the
3758 // minimum count.
3759 if (super.getMaximumIntegerDigits() > DOUBLE_INTEGER_DIGITS ||
3760 super.getMaximumFractionDigits() > DOUBLE_FRACTION_DIGITS) {
3761 throw new InvalidObjectException("Digit count out of range");
3762 }
3763 if (serialVersionOnStream < 3) {
3764 setMaximumIntegerDigits(super.getMaximumIntegerDigits());
3765 setMinimumIntegerDigits(super.getMinimumIntegerDigits());
3766 setMaximumFractionDigits(super.getMaximumFractionDigits());
3767 setMinimumFractionDigits(super.getMinimumFractionDigits());
3768 }
3769 if (serialVersionOnStream < 1) {
3770 // Didn't have exponential fields
3771 useExponentialNotation = false;
3772 }
3773 serialVersionOnStream = currentSerialVersion;
3774 }
3775
3776 //----------------------------------------------------------------------
3777 // INSTANCE VARIABLES
3778 //----------------------------------------------------------------------
3779
3780 private transient DigitList digitList = new DigitList();
3781
3782 /**
3783 * The symbol used as a prefix when formatting positive numbers, e.g. "+".
3784 *
3785 * @serial
3786 * @see #getPositivePrefix
3787 */
3788 private String positivePrefix = "";
3789
3790 /**
3791 * The symbol used as a suffix when formatting positive numbers.
3792 * This is often an empty string.
3793 *
3794 * @serial
3795 * @see #getPositiveSuffix
3796 */
3797 private String positiveSuffix = "";
3798
3799 /**
3800 * The symbol used as a prefix when formatting negative numbers, e.g. "-".
3801 *
3802 * @serial
3803 * @see #getNegativePrefix
3804 */
3805 private String negativePrefix = "-";
3806
3807 /**
3808 * The symbol used as a suffix when formatting negative numbers.
3809 * This is often an empty string.
3810 *
3811 * @serial
3812 * @see #getNegativeSuffix
3813 */
3814 private String negativeSuffix = "";
3815
3816 /**
3817 * The prefix pattern for non-negative numbers. This variable corresponds
3818 * to <code>positivePrefix</code>.
3819 *
3820 * <p>This pattern is expanded by the method <code>expandAffix()</code> to
3821 * <code>positivePrefix</code> to update the latter to reflect changes in
3822 * <code>symbols</code>. If this variable is <code>null</code> then
3823 * <code>positivePrefix</code> is taken as a literal value that does not
3824 * change when <code>symbols</code> changes. This variable is always
3825 * <code>null</code> for <code>DecimalFormat</code> objects older than
3826 * stream version 2 restored from stream.
3827 *
3828 * @serial
3829 * @since 1.3
3830 */
3831 private String posPrefixPattern;
3832
3833 /**
3834 * The suffix pattern for non-negative numbers. This variable corresponds
3835 * to <code>positiveSuffix</code>. This variable is analogous to
3836 * <code>posPrefixPattern</code>; see that variable for further
3837 * documentation.
3838 *
3839 * @serial
3840 * @since 1.3
3841 */
3842 private String posSuffixPattern;
3843
3844 /**
3845 * The prefix pattern for negative numbers. This variable corresponds
3846 * to <code>negativePrefix</code>. This variable is analogous to
3847 * <code>posPrefixPattern</code>; see that variable for further
3848 * documentation.
3849 *
3850 * @serial
3851 * @since 1.3
3852 */
3853 private String negPrefixPattern;
3854
3855 /**
3856 * The suffix pattern for negative numbers. This variable corresponds
3857 * to <code>negativeSuffix</code>. This variable is analogous to
3858 * <code>posPrefixPattern</code>; see that variable for further
3859 * documentation.
3860 *
3861 * @serial
3862 * @since 1.3
3863 */
3864 private String negSuffixPattern;
3865
3866 /**
3867 * The multiplier for use in percent, per mille, etc.
3868 *
3869 * @serial
3870 * @see #getMultiplier
3871 */
3872 private int multiplier = 1;
3873
3874 /**
3875 * The number of digits between grouping separators in the integer
3876 * portion of a number. Must be greater than 0 if
3877 * <code>NumberFormat.groupingUsed</code> is true.
3878 *
3879 * @serial
3880 * @see #getGroupingSize
3881 * @see java.text.NumberFormat#isGroupingUsed
3882 */
3883 private byte groupingSize = 3; // invariant, > 0 if useThousands
3884
3885 /**
3886 * If true, forces the decimal separator to always appear in a formatted
3887 * number, even if the fractional part of the number is zero.
3888 *
3889 * @serial
3890 * @see #isDecimalSeparatorAlwaysShown
3891 */
3892 private boolean decimalSeparatorAlwaysShown = false;
3893
3894 /**
3895 * If true, parse returns BigDecimal wherever possible.
3896 *
3897 * @serial
3898 * @see #isParseBigDecimal
3899 * @since 1.5
3900 */
3901 private boolean parseBigDecimal = false;
3902
3903
3904 /**
3905 * True if this object represents a currency format. This determines
3906 * whether the monetary decimal separator is used instead of the normal one.
3907 */
3908 private transient boolean isCurrencyFormat = false;
3909
3910 /**
3911 * The <code>DecimalFormatSymbols</code> object used by this format.
3912 * It contains the symbols used to format numbers, e.g. the grouping separator,
3913 * decimal separator, and so on.
3914 *
3915 * @serial
3916 * @see #setDecimalFormatSymbols
3917 * @see java.text.DecimalFormatSymbols
3918 */
3919 private DecimalFormatSymbols symbols = null; // LIU new DecimalFormatSymbols();
3920
3921 /**
3922 * True to force the use of exponential (i.e. scientific) notation when formatting
3923 * numbers.
3924 *
3925 * @serial
3926 * @since 1.2
3927 */
3928 private boolean useExponentialNotation; // Newly persistent in the Java 2 platform v.1.2
3929
3930 /**
3931 * FieldPositions describing the positive prefix String. This is
3932 * lazily created. Use <code>getPositivePrefixFieldPositions</code>
3933 * when needed.
3934 */
3935 private transient FieldPosition[] positivePrefixFieldPositions;
3936
3937 /**
3938 * FieldPositions describing the positive suffix String. This is
3939 * lazily created. Use <code>getPositiveSuffixFieldPositions</code>
3940 * when needed.
3941 */
3942 private transient FieldPosition[] positiveSuffixFieldPositions;
3943
3944 /**
3945 * FieldPositions describing the negative prefix String. This is
3946 * lazily created. Use <code>getNegativePrefixFieldPositions</code>
3947 * when needed.
3948 */
3949 private transient FieldPosition[] negativePrefixFieldPositions;
3950
3951 /**
3952 * FieldPositions describing the negative suffix String. This is
3953 * lazily created. Use <code>getNegativeSuffixFieldPositions</code>
3954 * when needed.
3955 */
3956 private transient FieldPosition[] negativeSuffixFieldPositions;
3957
3958 /**
3959 * The minimum number of digits used to display the exponent when a number is
3960 * formatted in exponential notation. This field is ignored if
3961 * <code>useExponentialNotation</code> is not true.
3962 *
3963 * @serial
3964 * @since 1.2
3965 */
3966 private byte minExponentDigits; // Newly persistent in the Java 2 platform v.1.2
3967
3968 /**
3969 * The maximum number of digits allowed in the integer portion of a
3970 * <code>BigInteger</code> or <code>BigDecimal</code> number.
3971 * <code>maximumIntegerDigits</code> must be greater than or equal to
3972 * <code>minimumIntegerDigits</code>.
3973 *
3974 * @serial
3975 * @see #getMaximumIntegerDigits
3976 * @since 1.5
3977 */
3978 private int maximumIntegerDigits = super.getMaximumIntegerDigits();
3979
3980 /**
3981 * The minimum number of digits allowed in the integer portion of a
3982 * <code>BigInteger</code> or <code>BigDecimal</code> number.
3983 * <code>minimumIntegerDigits</code> must be less than or equal to
3984 * <code>maximumIntegerDigits</code>.
3985 *
3986 * @serial
3987 * @see #getMinimumIntegerDigits
3988 * @since 1.5
3989 */
3990 private int minimumIntegerDigits = super.getMinimumIntegerDigits();
3991
3992 /**
3993 * The maximum number of digits allowed in the fractional portion of a
3994 * <code>BigInteger</code> or <code>BigDecimal</code> number.
3995 * <code>maximumFractionDigits</code> must be greater than or equal to
3996 * <code>minimumFractionDigits</code>.
3997 *
3998 * @serial
3999 * @see #getMaximumFractionDigits
4000 * @since 1.5
4001 */
4002 private int maximumFractionDigits = super.getMaximumFractionDigits();
4003
4004 /**
4005 * The minimum number of digits allowed in the fractional portion of a
4006 * <code>BigInteger</code> or <code>BigDecimal</code> number.
4007 * <code>minimumFractionDigits</code> must be less than or equal to
4008 * <code>maximumFractionDigits</code>.
4009 *
4010 * @serial
4011 * @see #getMinimumFractionDigits
4012 * @since 1.5
4013 */
4014 private int minimumFractionDigits = super.getMinimumFractionDigits();
4015
4016 /**
4017 * The {@link java.math.RoundingMode} used in this DecimalFormat.
4018 *
4019 * @serial
4020 * @since 1.6
4021 */
4022 private RoundingMode roundingMode = RoundingMode.HALF_EVEN;
4023
4024 // ------ DecimalFormat fields for fast-path for double algorithm ------
4025
4026 /**
4027 * Helper inner utility class for storing the data used in the fast-path
4028 * algorithm. Almost all fields related to fast-path are encapsulated in
4029 * this class.
4030 *
4031 * Any {@code DecimalFormat} instance has a {@code fastPathData}
4032 * reference field that is null unless both the properties of the instance
4033 * are such that the instance is in the "fast-path" state, and a format call
4034 * has been done at least once while in this state.
4035 *
4036 * Almost all fields are related to the "fast-path" state only and don't
4037 * change until one of the instance properties is changed.
4038 *
4039 * {@code firstUsedIndex} and {@code lastFreeIndex} are the only
4040 * two fields that are used and modified while inside a call to
4041 * {@code fastDoubleFormat}.
4042 *
4043 */
4044 private static class FastPathData {
4045 // --- Temporary fields used in fast-path, shared by several methods.
4046
4047 /** The first unused index at the end of the formatted result. */
4048 int lastFreeIndex;
4049
4050 /** The first used index at the beginning of the formatted result */
4051 int firstUsedIndex;
4052
4053 // --- State fields related to fast-path status. Changes due to a
4054 // property change only. Set by checkAndSetFastPathStatus() only.
4055
4056 /** Difference between locale zero and default zero representation. */
4057 int zeroDelta;
4058
4059 /** Locale char for grouping separator. */
4060 char groupingChar;
4061
4062 /** Fixed index position of last integral digit of formatted result */
4063 int integralLastIndex;
4064
4065 /** Fixed index position of first fractional digit of formatted result */
4066 int fractionalFirstIndex;
4067
4068 /** Fractional constants depending on decimal|currency state */
4069 double fractionalScaleFactor;
4070 int fractionalMaxIntBound;
4071
4072
4073 /** The char array buffer that will contain the formatted result */
4074 char[] fastPathContainer;
4075
4076 /** Suffixes recorded as char array for efficiency. */
4077 char[] charsPositivePrefix;
4078 char[] charsNegativePrefix;
4079 char[] charsPositiveSuffix;
4080 char[] charsNegativeSuffix;
4081 boolean positiveAffixesRequired = true;
4082 boolean negativeAffixesRequired = true;
4083 }
4084
4085 /** The format fast-path status of the instance. Logical state. */
4086 private transient boolean isFastPath = false;
4087
4088 /** Flag stating need of check and reinit fast-path status on next format call. */
4089 private transient boolean fastPathCheckNeeded = true;
4090
4091 /** DecimalFormat reference to its FastPathData */
4092 private transient FastPathData fastPathData;
4093
4094
4095 //----------------------------------------------------------------------
4096
4097 static final int currentSerialVersion = 4;
4098
4099 /**
4100 * The internal serial version which says which version was written.
4101 * Possible values are:
4102 * <ul>
4103 * <li><b>0</b> (default): versions before the Java 2 platform v1.2
4104 * <li><b>1</b>: version for 1.2, which includes the two new fields
4105 * <code>useExponentialNotation</code> and
4106 * <code>minExponentDigits</code>.
4107 * <li><b>2</b>: version for 1.3 and later, which adds four new fields:
4108 * <code>posPrefixPattern</code>, <code>posSuffixPattern</code>,
4109 * <code>negPrefixPattern</code>, and <code>negSuffixPattern</code>.
4110 * <li><b>3</b>: version for 1.5 and later, which adds five new fields:
4111 * <code>maximumIntegerDigits</code>,
4112 * <code>minimumIntegerDigits</code>,
4113 * <code>maximumFractionDigits</code>,
4114 * <code>minimumFractionDigits</code>, and
4115 * <code>parseBigDecimal</code>.
4116 * <li><b>4</b>: version for 1.6 and later, which adds one new field:
4117 * <code>roundingMode</code>.
4118 * </ul>
4119 * @since 1.2
4120 * @serial
4121 */
4122 private int serialVersionOnStream = currentSerialVersion;
4123
4124 //----------------------------------------------------------------------
4125 // CONSTANTS
4126 //----------------------------------------------------------------------
4127
4128 // ------ Fast-Path for double Constants ------
4129
4130 /** Maximum valid integer value for applying fast-path algorithm */
4131 private static final double MAX_INT_AS_DOUBLE = (double) Integer.MAX_VALUE;
4132
4133 /**
4134 * The digit arrays used in the fast-path methods for collecting digits.
4135 * Using 3 constants arrays of chars ensures a very fast collection of digits
4136 */
4137 private static class DigitArrays {
4138 static final char[] DigitOnes1000 = new char[1000];
4139 static final char[] DigitTens1000 = new char[1000];
4140 static final char[] DigitHundreds1000 = new char[1000];
4141
4142 // initialize on demand holder class idiom for arrays of digits
4143 static {
4144 int tenIndex = 0;
4145 int hundredIndex = 0;
4146 char digitOne = '0';
4147 char digitTen = '0';
4148 char digitHundred = '0';
4149 for (int i = 0; i < 1000; i++ ) {
4150
4151 DigitOnes1000[i] = digitOne;
4152 if (digitOne == '9')
4153 digitOne = '0';
4154 else
4155 digitOne++;
4156
4157 DigitTens1000[i] = digitTen;
4158 if (i == (tenIndex + 9)) {
4159 tenIndex += 10;
4160 if (digitTen == '9')
4161 digitTen = '0';
4162 else
4163 digitTen++;
4164 }
4165
4166 DigitHundreds1000[i] = digitHundred;
4167 if (i == (hundredIndex + 99)) {
4168 digitHundred++;
4169 hundredIndex += 100;
4170 }
4171 }
4172 }
4173 }
4174 // ------ Fast-Path for double Constants end ------
4175
4176 // Constants for characters used in programmatic (unlocalized) patterns.
4177 private static final char PATTERN_ZERO_DIGIT = '0';
4178 private static final char PATTERN_GROUPING_SEPARATOR = ',';
4179 private static final char PATTERN_DECIMAL_SEPARATOR = '.';
4180 private static final char PATTERN_PER_MILLE = '\u2030';
4181 private static final char PATTERN_PERCENT = '%';
4182 private static final char PATTERN_DIGIT = '#';
4183 private static final char PATTERN_SEPARATOR = ';';
4184 private static final String PATTERN_EXPONENT = "E";
4185 private static final char PATTERN_MINUS = '-';
4186
4187 /**
4188 * The CURRENCY_SIGN is the standard Unicode symbol for currency. It
4189 * is used in patterns and substituted with either the currency symbol,
4190 * or if it is doubled, with the international currency symbol. If the
4191 * CURRENCY_SIGN is seen in a pattern, then the decimal separator is
4192 * replaced with the monetary decimal separator.
4193 *
4194 * The CURRENCY_SIGN is not localized.
4195 */
4196 private static final char CURRENCY_SIGN = '\u00A4';
4197
4198 private static final char QUOTE = '\'';
4199
4200 private static FieldPosition[] EmptyFieldPositionArray = new FieldPosition[0];
4201
4202 // Upper limit on integer and fraction digits for a Java double
4203 static final int DOUBLE_INTEGER_DIGITS = 309;
4204 static final int DOUBLE_FRACTION_DIGITS = 340;
4205
4206 // Upper limit on integer and fraction digits for BigDecimal and BigInteger
4207 static final int MAXIMUM_INTEGER_DIGITS = Integer.MAX_VALUE;
4208 static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;
4209
4210 // Proclaim JDK 1.1 serial compatibility.
4211 static final long serialVersionUID = 864413376551465018L;
4212 }
来源：https://www.cnblogs.com/XT-xutao/p/9882404.html