Command Prompt / Console

Question

Hi, I am building a personalised java development environment and have come unstuck.
I wish to create a JPanel that behaves very much like a console window allowing execution of commands (taken from a JTextField) and displaying standard output and standard error.
my console almost outputs the standard output and standard error, although it sometimes truncates the first character and replaces it with a line feed (sometimes...??). my main problem is that i cant figure out how to execute a command on System eg "echo hello" so that my console behaves properly and returns the standard output.
below is the code for my JPanel, an important section to view would be the ActionListener attached to my JTextField.
thanks for reading this far :)
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
public class ConsoleOutput extends JPanel
     final Color TEXTBG= new Color(0, 0, 100);
     final Color TEXTFG= new Color(200, 200, 200);
     PipedInputStream piOut;
     PipedInputStream piErr;
     PipedOutputStream poOut;
     PipedOutputStream poErr;
     JTextArea textArea = new JTextArea();
     JTextField inputField = new JTextField();
     Font outputFont = new Font("Monospace", Font.PLAIN, 10);
     Font inputFont = new Font("Monospace", Font.BOLD, 12);
     public ConsoleOutput() throws IOException
          this.setPreferredSize(new Dimension(450,700));
          this.setBackground(Xjde.BGCOLOR);
          // Set up text area
          textArea.setBorder(BorderFactory.createEmptyBorder());
          textArea.setEditable(false);
          textArea.setPreferredSize(new Dimension(450,650));
          textArea.setBackground(TEXTBG);
          textArea.setForeground(TEXTFG);
          textArea.setFont(outputFont);
          // Set up input field
          inputField.setBorder(BorderFactory.createEmptyBorder());
          inputField.setPreferredSize(new Dimension(450,30));
          inputField.setBackground(TEXTBG);
          inputField.setForeground(TEXTFG);
          inputField.setFont(inputFont);
          inputField.addActionListener(new ActionListener()
               public void actionPerformed(ActionEvent evt)
                    textArea.append(inputField.getText() + "\n");
                    try
                         Process p = Runtime.getRuntime().exec(inputField.getText());
                    catch(IOException e) { System.out.println(e); }
                    inputField.setText("");
          // Set up System.out
          piOut = new PipedInputStream();
          poOut = new PipedOutputStream(piOut);
          System.setOut(new PrintStream(poOut, true));
          // Set up System.err
          piErr = new PipedInputStream();
          poErr = new PipedOutputStream(piErr);
          System.setErr(new PrintStream(poErr, true));
          // Create reader threads
          new ReaderThread(piOut).start();
          new ReaderThread(piErr).start();
          this.add(textArea);
          this.add(inputField);
          textArea.append("Welcome to Xjde v1.0 Java Development Environment\nEdd Burgess 2007\n");
          textArea.append("\n" + System.getProperty("user.dir") + ">");
          textArea.setCaretPosition(textArea.getDocument().getLength());
     class ReaderThread extends Thread
          PipedInputStream pi;
          ReaderThread(PipedInputStream pi)
               this.pi = pi;
               this.setDaemon(true);
          public void run()
               final byte[] buf = new byte[1024];
               try
                    while (true)
                         final int len = pi.read(buf);
                         if (len == -1)
                              break;
                         SwingUtilities.invokeLater(new Runnable()
                              public void run()
                                   textArea.append(new String(buf, 0, len));
                                   textArea.setCaretPosition(textArea.getDocument().getLength());
                                   // Keep the text area down to a certain character size
                                   //int idealSize = 1000;
                                   //int maxExcess = 500;
                                   //int excess = textArea.getDocument().getLength() - idealSize;
                                   //if (excess >= maxExcess)
                                   //     textArea.replaceRange("", 0, excess);
               catch (IOException e)
          public void newLine()
               textArea.append("\n" + System.getProperty("user.dir") + ">");
               textArea.setCaretPosition(textArea.getDocument().getLength());
}

Answer 1

web definition of 'come unstuck' :
come unstuck (British & Australian)
if a person or something they are trying to achieve comes unstuck, they have problems which cause them to fail. Athletes who don't prepare properly for the humid conditions will certainly come unstuck. The negotiations came unstuck over disagreements about the wording.