Re: Redirecting System.out and exotic characters

From:
=?ISO-8859-1?Q?Fran=E7ois_R?= <rappazf@gmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Thu, 5 Nov 2009 07:28:59 -0800 (PST)
Message-ID:
<5cd2ce42-7584-4d9f-a16b-742bc1322598@j4g2000yqe.googlegroups.com>
On Nov 4, 1:25 pm, Mayeul <mayeul.marg...@free.fr> wrote:

Fran=C3=A7ois R wrote:

This works well except when I have a character like =C4=8C (latin capit=

al

letter C with caron, '\u010C') in a string, which is displayed as ? in
the text area whereas
msg.append(string); would be ok.
How could I correct the code above to have such a letter well
formed ?


You have a character encoding problem.

Both the constructors PrintStream(OutputStream,boolean) and
String(byte[]) assume you're using your platform's default character
encoding to translate chars to bytes and vice-versa.

I expect your platform's default character to _not_ handle characters
such as U+10C, hence them being replaced with question marks.

The fix is to specify a character encoding to use, a unicode one, for
instance utf-8.

You can do that by constructing your PrintStream this way:

new PrintStream(new TextAreaOutputStream(msg), true, "utf-8")

And implementing your TextAreaOutputStream differently : it should store
the bytes in a buffer and wait til the OutputStream is flushed, thus
probably aligned after a character's final byte, then transform the
bytes received into a String and update the TextArea with it.

This could be done by writing the bytes you receive to a
ByteArrayOutputStream, and whenever it is flushed, fetch the byte[] and
build a String with it as such:

new String(bytes, "utf-8")

Note: one may think that using utf-16 instead of utf-8 would guarantee a
character to be 2-bytes and thus the solution easier to implement.
Except that *really* special characters (higher-than-U+FFFF characters)
still are be 4-bytes instead of 2-bytes with utf-16.
ucs-4 may work better if well-supported, I'm not sure.

--
Mayeul


Thanks a lot for the suggestion !
I tried this:
    try {
        System.setOut(new PrintStream(new TextAreaOutputStream(msg), true,
"utf-8"));
    } catch ....

and

private class TextAreaOutputStream extends OutputStream {
    JTextArea textArea;
    ByteArrayOutputStream buffer = new ByteArrayOutputStream();
TextAreaOutputStream(JTextArea textArea) {
    this.textArea = textArea;
}

 public void flush() {
    //textArea.repaint();
    try {
        textArea.append(buffer.toString("utf-8"));
        buffer.reset();
    } catch (UnsupportedEncodingException e){e.printStackTrace();}
 }
 public void write(int b) {
     buffer.write(b);
     //try {
  //textArea.append(new String(new byte[] {(byte)b}));
    // } catch (UnsupportedEncodingException e){e.printStackTrace();}
 }

}

And it works well as it seems, with name like C=C3=AD=C5=BEek or =C4=8C=C3=
=AD=C5=BEek properly
displayed.

Fran=C3=A7ois

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