问题
I am using an HTML form which sends
<input type=hidden name=longdesc value='SMARTNET%^" 8X5XNBD'>
this is done by the following javascript code:
function masinsert(id)
{
var currentTime=new Date();
var button = document.getElementById("m"+id);
button.onclick="";
button.value="Inserting";
var itemdescription = document.getElementById("itemdescription"+id).value;
function handleHttpResponse()
{
if (http.readyState == 4) {
button.value="Item Added";
}
}
var http = getHTTPObject(); // We create the HTTP Object
var tempUrl = "\AInsert";
tempUrl += "itemdescription="+itemdescription+"&"+"itemshortdescription="+itemdescription.substring(0,37)+;
alert(tempUrl);
http.open("GET", tempUrl, true);
http.onreadystatechange = handleHttpResponse;
http.send(null);
}
to a java servlet. AInsert.java
in the AInsert.java file, I do a
String itemdescription = request.getParameter("longdesc");
which then sends the value to a preparedstatement to run an insert query. In the query, there are sometimes special characters which throw it off. For example, when I run the following
insert into itemdescription (longdesc) values ('SMARTNET%^" 8X5XNBD')
here is the actual snippet:
PreparedStatement ps = conn.prepareStatement("INSERT INTO itemdescription (longdesc) values(?)");
ps.setString(1, itemdescription);
ps.executeUpdate();
It will produce an error saying : Cannot insert the value NULL into column 'LongDesc', table 'App.dbo.itemdescription'; column does not allow nulls. Insert fails
I have tried urlencode/urldecode
String encodedString = URLEncoder.encode(longdesc, "UTF-8");
String decitemdescription = URLDecoder.decode(itemdescription, "UTF-8");
and i've also tried these functions
//BEGIN URL Encoder
final static String[] hex = {
"%00", "%01", "%02", "%03", "%04", "%05", "%06", "%07",
"%08", "%09", "%0a", "%0b", "%0c", "%0d", "%0e", "%0f",
"%10", "%11", "%12", "%13", "%14", "%15", "%16", "%17",
"%18", "%19", "%1a", "%1b", "%1c", "%1d", "%1e", "%1f",
"%20", "%21", "%22", "%23", "%24", "%25", "%26", "%27",
"%28", "%29", "%2a", "%2b", "%2c", "%2d", "%2e", "%2f",
"%30", "%31", "%32", "%33", "%34", "%35", "%36", "%37",
"%38", "%39", "%3a", "%3b", "%3c", "%3d", "%3e", "%3f",
"%40", "%41", "%42", "%43", "%44", "%45", "%46", "%47",
"%48", "%49", "%4a", "%4b", "%4c", "%4d", "%4e", "%4f",
"%50", "%51", "%52", "%53", "%54", "%55", "%56", "%57",
"%58", "%59", "%5a", "%5b", "%5c", "%5d", "%5e", "%5f",
"%60", "%61", "%62", "%63", "%64", "%65", "%66", "%67",
"%68", "%69", "%6a", "%6b", "%6c", "%6d", "%6e", "%6f",
"%70", "%71", "%72", "%73", "%74", "%75", "%76", "%77",
"%78", "%79", "%7a", "%7b", "%7c", "%7d", "%7e", "%7f",
"%80", "%81", "%82", "%83", "%84", "%85", "%86", "%87",
"%88", "%89", "%8a", "%8b", "%8c", "%8d", "%8e", "%8f",
"%90", "%91", "%92", "%93", "%94", "%95", "%96", "%97",
"%98", "%99", "%9a", "%9b", "%9c", "%9d", "%9e", "%9f",
"%a0", "%a1", "%a2", "%a3", "%a4", "%a5", "%a6", "%a7",
"%a8", "%a9", "%aa", "%ab", "%ac", "%ad", "%ae", "%af",
"%b0", "%b1", "%b2", "%b3", "%b4", "%b5", "%b6", "%b7",
"%b8", "%b9", "%ba", "%bb", "%bc", "%bd", "%be", "%bf",
"%c0", "%c1", "%c2", "%c3", "%c4", "%c5", "%c6", "%c7",
"%c8", "%c9", "%ca", "%cb", "%cc", "%cd", "%ce", "%cf",
"%d0", "%d1", "%d2", "%d3", "%d4", "%d5", "%d6", "%d7",
"%d8", "%d9", "%da", "%db", "%dc", "%dd", "%de", "%df",
"%e0", "%e1", "%e2", "%e3", "%e4", "%e5", "%e6", "%e7",
"%e8", "%e9", "%ea", "%eb", "%ec", "%ed", "%ee", "%ef",
"%f0", "%f1", "%f2", "%f3", "%f4", "%f5", "%f6", "%f7",
"%f8", "%f9", "%fa", "%fb", "%fc", "%fd", "%fe", "%ff"
};
/**
* Encode a string to the "x-www-form-urlencoded" form, enhanced
* with the UTF-8-in-URL proposal. This is what happens:
*
* <ul>
* <li><p>The ASCII characters 'a' through 'z', 'A' through 'Z',
* and '0' through '9' remain the same.
*
* <li><p>The unreserved characters - _ . ! ~ * ' ( ) remain the same.
*
* <li><p>The space character ' ' is converted into a plus sign '+'.
*
* <li><p>All other ASCII characters are converted into the
* 3-character string "%xy", where xy is
* the two-digit hexadecimal representation of the character
* code
*
* <li><p>All non-ASCII characters are encoded in two steps: first
* to a sequence of 2 or 3 bytes, using the UTF-8 algorithm;
* secondly each of these bytes is encoded as "%xx".
* </ul>
*
* @param s The string to be encoded
* @return The encoded string
*/
public static String encode(String s)
{
StringBuffer sbuf = new StringBuffer();
int len = s.length();
for (int i = 0; i < len; i++) {
int ch = s.charAt(i);
if ('A' <= ch && ch <= 'Z') { // 'A'..'Z'
sbuf.append((char)ch);
} else if ('a' <= ch && ch <= 'z') { // 'a'..'z'
sbuf.append((char)ch);
} else if ('0' <= ch && ch <= '9') { // '0'..'9'
sbuf.append((char)ch);
} else if (ch == ' ') { // space
sbuf.append('+');
} else if (ch == '-' || ch == '_' // unreserved
|| ch == '.' || ch == '!'
|| ch == '~' || ch == '*'
|| ch == '\'' || ch == '('
|| ch == ')') {
sbuf.append((char)ch);
} else if (ch <= 0x007f) { // other ASCII
sbuf.append(hex[ch]);
} else if (ch <= 0x07FF) { // non-ASCII <= 0x7FF
sbuf.append(hex[0xc0 | (ch >> 6)]);
sbuf.append(hex[0x80 | (ch & 0x3F)]);
} else { // 0x7FF < ch <= 0xFFFF
sbuf.append(hex[0xe0 | (ch >> 12)]);
sbuf.append(hex[0x80 | ((ch >> 6) & 0x3F)]);
sbuf.append(hex[0x80 | (ch & 0x3F)]);
}
}
return sbuf.toString();
} //end encode
and
//decode url
private static String unescape(String s) {
StringBuffer sbuf = new StringBuffer () ;
int l = s.length() ;
int ch = -1 ;
int b, sumb = 0;
for (int i = 0, more = -1 ; i < l ; i++) {
/* Get next byte b from URL segment s */
switch (ch = s.charAt(i)) {
case '%':
ch = s.charAt (++i) ;
int hb = (Character.isDigit ((char) ch)
? ch - '0'
: 10+Character.toLowerCase((char) ch) - 'a') & 0xF ;
ch = s.charAt (++i) ;
int lb = (Character.isDigit ((char) ch)
? ch - '0'
: 10+Character.toLowerCase ((char) ch)-'a') & 0xF ;
b = (hb << 4) | lb ;
break ;
case '+':
b = ' ' ;
break ;
default:
b = ch ;
}
/* Decode byte b as UTF-8, sumb collects incomplete chars */
if ((b & 0xc0) == 0x80) { // 10xxxxxx (continuation byte)
sumb = (sumb << 6) | (b & 0x3f) ; // Add 6 bits to sumb
if (--more == 0) sbuf.append((char) sumb) ; // Add char to sbuf
} else if ((b & 0x80) == 0x00) { // 0xxxxxxx (yields 7 bits)
sbuf.append((char) b) ; // Store in sbuf
} else if ((b & 0xe0) == 0xc0) { // 110xxxxx (yields 5 bits)
sumb = b & 0x1f;
more = 1; // Expect 1 more byte
} else if ((b & 0xf0) == 0xe0) { // 1110xxxx (yields 4 bits)
sumb = b & 0x0f;
more = 2; // Expect 2 more bytes
} else if ((b & 0xf8) == 0xf0) { // 11110xxx (yields 3 bits)
sumb = b & 0x07;
more = 3; // Expect 3 more bytes
} else if ((b & 0xfc) == 0xf8) { // 111110xx (yields 2 bits)
sumb = b & 0x03;
more = 4; // Expect 4 more bytes
} else /*if ((b & 0xfe) == 0xfc)*/ { // 1111110x (yields 1 bit)
sumb = b & 0x01;
more = 5; // Expect 5 more bytes
}
/* We don't test if the UTF-8 encoding is well-formed */
}
return sbuf.toString() ;
}
but the decoding doesn't change it back to the original special characters.
Any ideas?
thanks in advance
UPDATE: I tried adding these two statements to grab the request
String itemdescription = URLDecoder.decode(request.getParameter("itemdescription"), "UTF-8");
String itemshortdescription = URLDecoder.decode(request.getParameter("itemshortdescription"), "UTF-8");
System.out.println("processRequest | short descrip ");
and this is failing as well if that helps.
UPDATE2: I created an html form and did a direct insert with the encoded itemdescription such as
and the insertion works correctly with the special charaters and everything. I guess there is something going on with my javascript submit. Any ideas on this?
回答1:
If you're using PreparedStatement, why aren't you using bound variables?
insert into itemdescription (longdesc) values ('SMARTNET%^" 8X5XNBD')
Should be
PreparedStatement ps = conn.prepareStatement("INSERT INTO itemdescription (longdesc) values(?)");
ps.setString(1, itemdescription);
ps.executeUpdate();
回答2:
Looks like the url you are building in your javascript isn't setting itemdescription as a request parameter correctly. itemdescription should be prefixed with a '?' character as it is the first parameter in the url query string. This should work:
var tempUrl = "\AInsert";
tempUrl += "?itemdescription="+itemdescription+"&"+"itemshortdescription="+itemdescription.substring(0,37)+;
来源：https://stackoverflow.com/questions/945543/java-inserting-special-characters-with-preparedstatement-fails