How to redirect javax.mail.Session setDebug to jTextArea

Question

How can I redirect javax.mail.Session setDebug to jTextArea ?

ByteArrayOutputStream os = new ByteArrayOutputStream();
PrintStream ps = new PrintStream(os);
Session mailSession = Session.getDefaultInstance(props, null);
logger.info("JAVAMAIL debug mode is ON");
mailSession.setDebug(true);
mailSession.setDebugOut(ps);
logger.info(os);

Answer 1

You could use the nice CustomOutputStream class described on http://www.codejava.net/java-se/swing/redirect-standard-output-streams-to-jtextarea:

import java.io.*;
import java.util.Properties;
import javax.mail.Session;
import javax.swing.*;

public class PrintStream2TextArea {
    public static void main(final String[] arguments) {
        new PrintStream2TextArea().launchGui();
    }

    private void launchGui() {
        final JFrame frame = new JFrame("Stack Overflow");
        frame.setBounds(100, 100, 800, 600);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        final JTextArea textArea = new JTextArea(42, 28);
        setupMailSession(new Properties(), textArea);
        frame.getContentPane().add(textArea);
        frame.setVisible(true);
    }

    private void setupMailSession(final Properties props, final JTextArea textArea) {
        PrintStream ps = new PrintStream(new CustomOutputStream(textArea));
        Session mailSession = Session.getDefaultInstance(props, null);
        //logger.info("JAVAMAIL debug mode is ON");
        mailSession.setDebug(true);
        mailSession.setDebugOut(ps);
        //logger.info(os);
    }

    /**
     * This class extends from OutputStream to redirect output to a JTextArea.
     *
     * @author www.codejava.net
     */
    public static class CustomOutputStream extends OutputStream {
        private JTextArea textArea;

        public CustomOutputStream(JTextArea textArea) {
            this.textArea = textArea;
        }

        @Override
        public void write(int b) throws IOException {
            // redirects data to the text area
            textArea.append(String.valueOf((char)b));
            // scrolls the text area to the end of data
            textArea.setCaretPosition(textArea.getDocument().getLength());
        }
    }
}