问题
I'm working on a web monitoring project in Arabic and I want to convert string date like this one:
الاثنين 24 أبريل 2017 - 15:00
to Java 8 date object. How can I do that?
回答1:
Edit: with thanks to slim and Meno Hochschild for inspiration:
String dateTimeString = "الاثنين 24 أبريل 2017 - 15:00";
DateTimeFormatter formatter
= DateTimeFormatter.ofPattern("EEEE d MMMM uuuu - HH:mm", new Locale("ar"));
LocalDateTime dateTime = LocalDateTime.parse(dateTimeString, formatter);
System.out.println(dateTime);
This prints:
2017-04-24T15:00
回答2:
The answers of @Ole and @slim are working, but not for the reason they think.
First observation - the nu-extension is unnecessary for given example:
Oles suggestion would also work for the locale new Locale("ar", "SA") instead of Locale.forLanguageTag("ar-SA-u-nu-arab"). So what does the unicode-nu-extension here? Nothing. Next question:
What is the nu-extension supposed to do here?
The nu-code-word "arab" is specified by the unicode consortium to yield arabic-indic digits. But the input to be parsed does only have western digits 0-9 (which are historically overtaken from Arab people and specified as code word "latn" - a misnomer by the way). So if the nu-extension had really done its job here then parsing should have failed because arabic-indic digits are not 0-9 but:
٠ ١ ٢ ٣ ٤ ٥ ٦ ٧ ٨ ٩
Obviously, the nu-extension is not supported in general by new time-API in Java-8.
Does SimpleDateFormat support the nu-extension?
Using debugging of following code, I discovered that the nu-extension is only supported for Thai-numerals (see also official javadoc of class java.util.Locale but not for arabic-indic digits:
SimpleDateFormat sdf =
new SimpleDateFormat("EEEE d MMMM yyyy - HH:mm", Locale.forLanguageTag("ar-SA-nu-arab"));
Date d = sdf.parse(dateTimeString);
System.out.println(d);
String formatted = sdf.format(d);
System.out.println(formatted);
System.out.println(sdf.format(d).equals(dateTimeString));
sdf = new SimpleDateFormat("EEEE d MMMM uuuu - HH:mm", Locale.forLanguageTag("ar-SA-u-nu-thai"));
String thai = sdf.format(d);
System.out.println("u-nu-thai: " + thai);
I assume the class DateTimeFormatter of Java-8 also supports Thai numerals.
Conclusion:
Forget the nu-extension. Just construct the locale via the old-fashioned way without unicode extension and adapt Oles answer this way. It works because your input only has western digits 0-9.
For extensive i18n-support including the nu-extension for various numbering systems (if you have such input), you might consider external libraries (for example ICU4J or my lib Time4J).
回答3:
I don't know enough Arabic to understand an Arabic formatted date. However this code:
Locale arabicLocale = new Locale.Builder().setLanguageTag("ar-SA-u-nu-arab").build();
LocalDate date = LocalDate.now();
DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.FULL).withLocale(arabicLocale);
String formatted = date.format(formatter);
System.out.println(formatted);
System.out.println(formatter.parse(formatted));
Yields this output:
26 أبريل, 2017
{},ISO resolved to 2017-04-26
The code to create the Locale is from an answer to Setting Arabic numbering system locale doesn't show Arabic numbers
You can fine-tune this format by defining your own FormatStyle.
回答4:
You have to specify the charset when parsing the string, assuming that the date you want to parse will always be in the format you provided this would work :
public static Date getDate(String strDate) throws Exception{
strDate=new String(strDate.getBytes(),"UTF-8");
Map<String, Integer> months = new HashMap<>();
String JAN = new String("يناير".getBytes(), "UTF-8");
String FEB = new String("فبراير".getBytes(), "UTF-8");
String MAR = new String("مارس".getBytes(), "UTF-8");
String APR = new String("أبريل".getBytes(), "UTF-8");
String APR_bis = new String("ابريل".getBytes(), "UTF-8");
String MAY = new String("ماي".getBytes(), "UTF-8");
String JUN = new String("بونيو".getBytes(), "UTF-8");
String JUN_bis = new String("يونيه".getBytes(), "UTF-8");
String JUL = new String("يوليوز".getBytes(), "UTF-8");
String AUG = new String("غشت".getBytes(), "UTF-8");
String SEP = new String("شتنبر".getBytes(), "UTF-8");
String SEP_bis = new String("سبتمبر".getBytes(), "UTF-8");
String OCT = new String("أكتوبر".getBytes(), "UTF-8");
String OCT_bis = new String("اكتوبر".getBytes(), "UTF-8");
String NOV = new String("نونبر".getBytes(), "UTF-8");
String NOV_bis = new String("نوفمبر".getBytes(), "UTF-8");
String DEC = new String("دجنبر".getBytes(), "UTF-8");
String DEC_bis = new String("ديسمبر".getBytes(), "UTF-8");
months.put(JAN, 0);
months.put(FEB, 1);
months.put(MAR, 2);
months.put(APR, 3);
months.put(APR_bis, 3);
months.put(MAY, 4);
months.put(JUN, 5);
months.put(JUN_bis, 5);
months.put(JUL, 6);
months.put(AUG, 7);
months.put(SEP, 8);
months.put(SEP_bis, 8);
months.put(OCT, 9);
months.put(OCT_bis, 9);
months.put(NOV, 10);
months.put(NOV_bis, 10);
months.put(DEC, 11);
months.put(DEC_bis, 11);
StringTokenizer stringTokenizer = new StringTokenizer(strDate);
Calendar calendar = Calendar.getInstance();
while(stringTokenizer.hasMoreElements()) {
stringTokenizer.nextElement();// to skip the first string which is the name of the day
int day = Integer.parseInt(stringTokenizer.nextElement().toString().trim());
String strMonth = stringTokenizer.nextElement().toString().trim();
int month = months.get(strMonth);
int year = Integer.parseInt(stringTokenizer.nextElement().toString().trim());
calendar.set(year, month, day);
}
return calendar.getTime();
}
it gives this output :
Fri Oct 20 15:26:47 WEST 2017
回答5:
One solution could be to translate the date to English and parse it then:
private final static Map<String, Integer> monthMapping = new HashMap<>();
static {
// list of all month.
monthMapping.put("أبريل", "4");
}
public Date fromArabicToDate(String arabicInput) throws ParseException {
String[] parts = arabicInput.split(" ");
if (parts.length != 4)
throw new IllegalArgumentException();
String dateInput = parts[0] + "-" + monthMapping.get(parts[1]) + "-" + parts[2];
SimpleDateFormat parser = new SimpleDateFormat("YYYY-MM-DD");
return parser.parse(dateInput);
}
I tried to copy the month but I don't believe I have done it correctly. The arguments of put get switched when parsing.
Or you have a look at Joda-Time. Maybe they have a solution. It was mentioned here.
来源：https://stackoverflow.com/questions/43637680/how-do-i-convert-an-arabic-string-date-to-a-java-8-date-object