how can i display output text in a textArea of a jpanel

[sk said]

hello,
i have a tabbed pane with 3 jPanel.2 is for processing and another 1 is to display an output.
there is a button 'Generator' in both processing panel,after process the information,i want to display the output in a textarea in output panel.currently my code doesnt has error but the output doesnt displayed in textarea.this is my code (i show for 2 jpanel only).

package rtg;
import java.util.*;
import java.io.*;

public class SamplesJFrame extends javax.swing.JFrame {

    private String input = new String();
    /** Creates new form SamplesJFrame */
    public SamplesJFrame() {
        initComponents();
    }

     private void initComponents() {

        jTabbedPane1 = new javax.swing.JTabbedPane();
        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        jScrollPane1 = new javax.swing.JScrollPane();
        jTextArea1 = new javax.swing.JTextArea();
        jButton1 = new javax.swing.JButton();
        jScrollPane2 = new javax.swing.JScrollPane();
        jTextArea2 = new javax.swing.JTextArea();
        jTextField2 = new javax.swing.JTextField();
        jLabel3 = new javax.swing.JLabel();
        jButton2 = new javax.swing.JButton();
        jTextField1 = new javax.swing.JTextField();
        jPanel3 = new javax.swing.JPanel();
        jScrollPane4 = new javax.swing.JScrollPane();
        jTextArea4 = new javax.swing.JTextArea();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jLabel1.setText("Name of Parameter");

        jLabel2.setText("Values");

        jTextArea1.setColumns(20);
        jTextArea1.setRows(5);
        jScrollPane1.setViewportView(jTextArea1);

        jTextArea2.setColumns(20);
        jTextArea2.setEditable(false);
        jTextArea2.setRows(5);
        jScrollPane2.setViewportView(jTextArea2);

        jLabel3.setText("Strength");

        jButton2.setText("Generate");
        jButton2.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jButton2ActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            //layout setting
        );
        jPanel1Layout.setVerticalGroup(
           //jpanel1 grouping
        );

        jTabbedPane1.addTab("Actual Input", jPanel1);

        jTextArea4.setColumns(20);
        jTextArea4.setEditable(false);
        jTextArea4.setRows(5);
        jScrollPane4.setViewportView(jTextArea4);

        javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
        jPanel3.setLayout(jPanel3Layout);
        jPanel3Layout.setHorizontalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel3Layout.createSequentialGroup()
                .addGap(53, 53, 53)
                .addComponent(jScrollPane4, javax.swing.GroupLayout.PREFERRED_SIZE, 271, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(71, Short.MAX_VALUE))
        );
        jPanel3Layout.setVerticalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel3Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jScrollPane4, javax.swing.GroupLayout.PREFERRED_SIZE, 295, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(37, Short.MAX_VALUE))
        );

        jTabbedPane1.addTab("Output", jPanel3);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jTabbedPane1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jTabbedPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 371, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>

  
    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt)
    {
        // TODO add your handling code here:
        input = input.substring(0,input.length()-1);

	 			        Datamanager input_final = new Datamanager();
	 					input_final.setActualInput(input);
	 					String value_set = input_final.getFinalInput();

	 					Generator gen = new Generator();
	 					gen.insertSystemSetting(value_set);
	 					gen.insertStrength(Integer.parseInt(jTextField2.getText()));

	 					gen.solve();
	 					ArrayList<String> test_set = gen.getResult();

	 					input_final.setActualOutput(test_set);
	 					ArrayList<String> result_set = input_final.getActualResult(); 

                                                           //this is how i want to display the result.jTextArea4 is textarea in output panel (jpanel3)
	 								int j=1;
	 								for(Iterator it = result_set.iterator(); it.hasNext();)
	 			           			{
	 									String data = (String)it.next();
	 									jTextArea4.append(j+" => "+data+"\n");
	 									j++;
 								}

    }

   
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new SamplesJFrame().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton2;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JScrollPane jScrollPane2;
    private javax.swing.JScrollPane jScrollPane4;
    private javax.swing.JTabbedPane jTabbedPane1;
    private javax.swing.JTextArea jTextArea1;
    private javax.swing.JTextArea jTextArea2;
    private javax.swing.JTextArea jTextArea4;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    private javax.swing.JTextField jTextField4;
    // End of variables declaration
}

[Arun Chidam]

Have you added your output textarea in jpanel3, looking at your code there is not component added to jpanel3