java - Create a "Command" Console

Question

I have a bit of an unusual question: How can I create a "Command Console" using Swing?

What I want to have is a console where the users type in commands, press enter, and the output from the command is displayed under. I don't want to allow the user to change the "prompt" and older output. I am thinking of something like Windows CMD.EXE.

I had a look at this question, however it doesn't answer my question.

Answer 1

BeanShell provides a JConsole, a command line input console with the following features:

• a blinking cursor
• command history
• cut/copy/paste including selection with CTRL+arrow keys
• command completion
• Unicode character input
• coloured text output
• ...and it all comes wrapped in a scroll pane.

The BeanShell JARs are available from http://www.beanshell.org/download.html and the source is available via SVN from svn co http://ikayzo.org/svn/beanshell

For more info on JConsole see http://www.beanshell.org/manual/jconsole.html

Here is an example of using BeanShell's JConsole in your application:

import java.awt.Color;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.Reader;

import javax.swing.JFrame;

import bsh.util.GUIConsoleInterface;
import bsh.util.JConsole;

/** 
 * Example of using the BeanShell project's JConsole in
 * your own application.
 * 
 * JConsole is a command line input console that has support 
 * for command history, cut/copy/paste, a blinking cursor, 
 * command completion, Unicode character input, coloured text 
 * output and comes wrapped in a scroll pane.
 * 
 * For more info, see http://www.beanshell.org/manual/jconsole.html
 * 
 * @author tukushan
 */
public class JConsoleExample {

    public static void main(String[] args) {

        //define a frame and add a console to it
        JFrame frame = new JFrame("JConsole example");

        JConsole console = new JConsole();

        frame.getContentPane().add(console);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(600,400);

        frame.setVisible(true);

        inputLoop(console, "JCE (type 'quit' to exit): ");

        System.exit(0);
    }

    /**
     * Print prompt and echos commands entered via the JConsole
     * 
     * @param console a GUIConsoleInterface which in addition to 
     *         basic input and output also provides coloured text
     *         output and name completion
     * @param prompt text to display before each input line
     */
    private static void inputLoop(GUIConsoleInterface console, String prompt) {
        Reader input = console.getIn();
        BufferedReader bufInput = new BufferedReader(input);

        String newline = System.getProperty("line.separator");

        console.print(prompt, Color.BLUE);

        String line;
        try {
            while ((line = bufInput.readLine()) != null) {
                console.print("You typed: " + line + newline, Color.ORANGE);

                // try to sync up the console
                //System.out.flush();
                //System.err.flush();
                //Thread.yield();  // this helps a little

                if (line.equals("quit")) break; 
                console.print(prompt, Color.BLUE);
            }
            bufInput.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}

NB: JConsole returns ";" if you hit Enter by itself.