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rivera
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 Posted: Fri Oct 21, 2005 6:33 pm Post subject: OutputStream,Printwriter etc... help |
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hello everyone,
I am having trouble understanding the concept of PrintWriters and
OutputStreams for a program i'm writing.
What i have is a function that takes a printwriter as an argument and writes
to it. I can get it to work on System.out like this
PrintWriter out = new PrintWriter(System.out,true);
function(x,out);
this works perfectly but i dont need to System.out the result i need to
write it to a JTextArea, Can someone explain how i can possibly append the
printwriter to the TextArea object or save it to a string?
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Oliver Wong
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| Posted: Fri Oct 21, 2005 6:41 pm Post subject: Re: OutputStream,Printwriter etc... help |
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"rivera" <boosh (AT) pacbell (DOT) net> wrote
| Quote: | hello everyone,
I am having trouble understanding the concept of PrintWriters and
OutputStreams for a program i'm writing.
What i have is a function that takes a printwriter as an argument and
writes to it. I can get it to work on System.out like this
PrintWriter out = new PrintWriter(System.out,true);
function(x,out);
this works perfectly but i dont need to System.out the result i need to
write it to a JTextArea, Can someone explain how i can possibly append the
printwriter to the TextArea object or save it to a string?
|
How about something like:
<code>
StringWriter sw = new StringWriter();
PrintWriter out = new PrintWriter(sw,true);
function(x,out);
String s = sw.toString();
</code>
- Oliver
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Roedy Green
Guest
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| Posted: Sat Oct 22, 2005 1:22 am Post subject: Re: OutputStream,Printwriter etc... help |
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On Fri, 21 Oct 2005 18:33:32 GMT, "rivera" <boosh (AT) pacbell (DOT) net> wrote
or quoted :
| Quote: |
this works perfectly but i dont need to System.out the result i need to
write it to a JTextArea, Can someone explain how i can possibly append the
printwriter to the TextArea object or save it to a string?
|
I won't, but a program I wrote will. See
http://mindprod.com/applets/fileio.html
Tell it you want you want to output characters to an char buffer in
memory. Then you can convert that to a String and feed it to your
TextArea.
--
Canadian Mind Products, Roedy Green.
http://mindprod.com Again taking new Java programming contracts.
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Thomas Fritsch
Guest
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| Posted: Sat Oct 22, 2005 6:08 pm Post subject: Re: OutputStream,Printwriter etc... help |
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"rivera" <boosh (AT) pacbell (DOT) net> wrote:
| Quote: | hello everyone,
I am having trouble understanding the concept of PrintWriters and
OutputStreams for a program i'm writing.
What i have is a function that takes a printwriter as an argument and
writes to it. I can get it to work on System.out like this
PrintWriter out = new PrintWriter(System.out,true);
function(x,out);
this works perfectly but i dont need to System.out the result i need to
write it to a JTextArea, Can someone explain how i can possibly append the
printwriter to the TextArea object or save it to a string?
You may want to develop a subclass of java.io.Writer, which "prints" into a |
JTextArea. This is easier than one might think at first:
/////// begin source
public class TextAreaWriter extends Writer {
private JTextArea textArea;
public TextAreaWriter(JTextArea textArea) {
this.textArea = textArea;
}
public void write(char buf[], int off, int len) throws IOException {
if (textArea == null)
throw new IOException("already closed");
textArea.append(new String(buf, off, len));
textArea.setCaretPosition(textArea.getText().length());
}
public void flush() {
}
public void close() {
textArea = null;
}
}
////// end source
I suggest to re-read the details of the API doc of Writer (especially its 3
abstract methods) to understand why and how the above code works.
http://java.sun.com/j2se/1.4.2/docs/api/java/io/Writer.html
You can create a PrintWriter around it by
PrintWriter out = new PrintWriter(new TextAreaWriter(yourTextArea));
and use that like any PrintWriter
out.println("bla bla...");
--
"TFritsch$t-online:de".replace(':','.').replace('$','@')
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