Illegal character - CTRL-CHAR

Question

I am getting following exception from webservices:

com.ctc.wstx.exc.WstxUnexpectedCharException: Illegal character ((CTRL-CHAR, code 15))

I know the reason behind this, I am getting "Control Characters" in data I want to return. And in XML CTRL-CHAR are not allowed.

I searched for the solution, and many places I found the code to remove CTRL-CHAR.

The concern is shall I end up loss of data if I remove control characters from data?
I want the clean solution may encoding, instead of removing control char.

@sarnold : It is decimal, forgot to add information about it. — jaxb, Jan 31 '11 at 10:12
@OrangeDog : I am not sending binary data, I am returning plain text from DB. Don't know how but its having control char in it. — jaxb, Jan 31 '11 at 10:16
Then you need to locate and fix that problem, rather than obscuring the problem in another layer. — OrangeDog, Jan 31 '11 at 12:06

score 13 · Answer 1 · edited Sep 26 '19 at 09:27

13

I would do what OrangeDog suggest. But if you want to solve it in your code try:

replaceAll("[\\x00-\\x09\\x11\\x12\\x14-\\x1F\\x7F]", "")

\\x12 is the char.

edited Sep 26 '19 at 09:27

Draken

3,134
13
34
54

answered Jun 20 '11 at 11:00

ssedano

8,322
9
60
98

score 8 · Accepted Answer · edited May 03 '16 at 17:51

8

Thanks guys for you inputs. I am sharing solution might be helpful for others. The requirement was not to wipe out CONTROL CHAR, it should remain as it is in DB also and one WS sends it across n/w client should able to get the CONTROL CHAR. So I implemented the code as follow:

Encode strings using URLEncoder in Web-Service code.
At client Side decode it using URLDecoder

Sharing sample code and output bellow.
Sample code:

System.out.println("NewSfn");  
System.out.println(URLEncoder.encode("NewSfn", "UTF-8"));  
System.out.println(URLDecoder.decode("NewSfn", "UTF-8"));

Output:

NewSfn  
New%0FSfn  
NewSfn

So client will recieve CONTROL CHARs.

EDIT: Stack Exchange is not showing CONTROL CHAR above. NewSfn is like this New(CONTROL CHAR)Sfn.

edited May 03 '16 at 17:51

SkyWalker

28,384
14
74
132

answered Feb 17 '12 at 11:14

jaxb

2,077
3
20
32

1

For my case enter key symbol from DB data to sent jax-ws server. it working if using URLEncoder.encode(DB_input, "UTF-8")); URLEncoder.decode(DB_output, "UTF-8")); with out losing data. – Umanath Sep 17 '17 at 08:01
1

There are separate characters available to represent control characters for illustration purposes. In your case it would be ␏. – OrangeDog Jul 09 '19 at 15:18

score 7 · Answer 3 · answered Jan 31 '11 at 10:35

This error is being thrown by the Woodstox XML parser. The source code from the InputBootstrapper class looks like this:

protected void reportUnexpectedChar(int i, String msg)
    throws WstxException
{
    char c = (char) i;
    String excMsg;

    // WTF? JDK thinks null char is just fine as?!
    if (Character.isISOControl(c)) {
        excMsg = "Unexpected character (CTRL-CHAR, code "+i+")"+msg;
    } else {
        excMsg = "Unexpected character '"+c+"' (code "+i+")"+msg;
    }
    Location loc = getLocation();
    throw new WstxUnexpectedCharException(excMsg, loc, c);
}

Amusing comment aside, the Woodstox is performing some additional validation on top of the JDK parser, and is rejecting the ASCII character 15 as invalid.

As to why that character is there, we can't tell you that, it's in your data. Similarly, we can't tell you if removing that character will break anything, since again, it's your data. You can only establish that for yourself.

score 5 · Answer 4 · answered Jan 31 '11 at 12:13

5

If you have control characters in your text data then you need to solve that problem at its source.

The most likely causes are incorrect communication encodings (usually between database and app) or not sanitising user input.

answered Jan 31 '11 at 12:13

OrangeDog

36,653
12
122
207

score 1 · Answer 5 · answered Jul 14 '14 at 23:19

1

I found the same problem when I was passing null values for some of the parameters. I passed empty or wrench values instead and this error went away.

answered Jul 14 '14 at 23:19

colin

129
2

score 0 · Answer 6 · answered Dec 03 '18 at 08:45

0

I'm a bit confused by @ssedano's anwser, it seems to me he's trying to find all control chars from ASCII table 0x00 to 0x1F except for 0x0A (new line) and 0x0D (carriage return) plus 0x7F (del), then wouldn't ther regex be

replaceAll("[\\x00-\\x09\\x0B\\x0C\\x0E-\\x1F\\x7F]", "")

answered Dec 03 '18 at 08:45

user2562934

9
1

Please see the question: " I want the clean solution … instead of removing control char." See the accepted answer, also. So, this does not answer the question. (With more reputation, you could comment or edit the other answer that you are referring to. Or, even downvote it on the same basis.) – Tom Blodget Dec 03 '18 at 17:32

Illegal character - CTRL-CHAR

6 Answers6

Linked

Related