Re: Redirecting System.in , System.out to JTextArea

From:
Janusch <hvm_Rentenatus@web.de>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 25 Mar 2008 00:50:15 -0700 (PDT)
Message-ID:
<b19ed29f-17c5-4840-9445-7add52a4a692@p25g2000hsf.googlegroups.com>
On 23 Mrz., 06:03, ash <3ashm...@gmail.com> wrote:

Hello,

  I need to know how to redirect System.in and System.out to a
JTextArea. The following is my initial attempt to write it's code. I
know it's missing alot (maybe major) stuff.

--begin--
import javax.swing.*;
import java.awt.*;
import java.io.*;
import java.awt.event.*;

class ConsolePanel extends JPanel implements KeyListener{

        private JTextArea consoleTextArea;
        private ByteArrayInputStream inStream;
        private ByteArrayOutputStream outStream;
        //private byte[] bufferByteArray;

        public ConsolePanel()
        {
                super();

                outStream = new ByteArrayOutputStream();

             Runnable r = new Runnable() {
                 public void run() {
                     try {
                         while(outStream.size()!= 0)
                         {
                                consoleTextArea.setText(outStream.toString());
                         }
                     } catch (Exception ie) {
                         ie.printStackTrace();
                     }
                 }
                };
                new Thread(r).start();

                consoleTextArea = new JTextArea();
                setLayout(new GridLayout(1,1));

                this.setBorder(BorderFactory.createLineBorder(Color.gray));
                add(consoleTextArea);

        }

        public ByteArrayOutputStream getOutputStream()
        {
                return outStream;
        }

        public ByteArrayInputStream getInputStream()
        {

                return inStream;
        }

        public void keyTyped(KeyEvent e) {}

        public void keyReleased(KeyEvent e) {}

        public void keyPressed(KeyEvent e) {
                String line = "";

          int key = e.getKeyCode();
          if (key != KeyEvent.VK_ENTER) {
                        line += ""+ e.getKeyChar();
           }
           else
           {
                        try
                        {
                                inStream = new ByteArrayInputStream(line.getBytes());
                                //inStream.read(line.getBytes());
                        }catch(Exception exc)
                        {
                                exc.printStackTrace();
                        }

           }
     }

}

--end---

What i am trying to do is to connect an InputStream and and an
OutputStream to the textArea. After that is done , ill get the in/out
stream from another class by the methods "getOutputStream()" and
"getInputStream()" and do System.setIn() and System.setOut from the
class that got a hold of the stream objects by the previously
mentioned methods.

What am i doing wrong ? (I know im doing alot wrong , but im kinda new
to I/O).

Thanx in advance for ur help

Ahmed Ashmawy


Hi,

you have to use java.lang.System.

static void setErr(PrintStream err)
          Reassigns the "standard" error output stream.
static void setIn(InputStream in)
          Reassigns the "standard" input stream.

For Example:

/*init in public ConsolePanel()*/
System.setIn(new MyInPrintStream());
System.setErr(new MyErrPrintStream());

/*impementation*/
class MyInPrintStream implements PrintStream{

   Color col;

   MyInPrintStream(){col=Color.BLACK;}

   /*Implement PrintStream and send all input to consoleTextArea*/

}

class MyErrPrintStream extends MyInPrintStream implements PrintStream{
   MyInPrintStream(){col=Color.RED;}
}

Janusch

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