Develop Reference

(Fixed)JTable does not add a new row

My project is to create a small temporary database with users and their passwords, so everything is saved in a second window, which would have a JTable and a button return to the main window. The problem would be precisely in JTable, when registering a new user, it ends up replacing the first user and so on, and a new row is not added with its respective registration.
Main:
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedList;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
public class LoginGUI {
private static JPanel panel;
private static JFrame frame;
private static JLabel userLabel, passwordLabel;
private static JPasswordField passwordText;
private static JTextField userText;
private static JButton buttonRegister, buttonShow;
private static JLabel success;
//This is just for print in the console
private static final LinkedList<DataUser> array = new LinkedList();
private static String user, pass;
private static DataUser listUser;
private static Show show = new Show(); //Problem solved by instantiating this first
public static void main(String[] args) {
//Panel
panel = new JPanel();
frame = new JFrame();
frame.setSize(350, 200);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(panel);
panel.setLayout(null);
//User
userLabel = new JLabel("User");
userLabel.setBounds(10, 20, 80, 25);
panel.add(userLabel);
//Password
passwordLabel = new JLabel("Password");
passwordLabel.setBounds(10, 50, 80, 25);
panel.add(passwordLabel);
//Password TextField
passwordText = new JPasswordField();
passwordText.setBounds(100, 50, 165, 25);
panel.add(passwordText);
//User TextField
userText = new JTextField(20);
userText.setBounds(100, 20, 165, 25);
panel.add(userText);
//Register Button
buttonRegister = new JButton("Login");
buttonRegister.setBounds(10, 90, 80, 25);
panel.add(buttonRegister);
RegisterButtonListener registerButtonListener = new RegisterButtonListener();
buttonRegister.addActionListener(registerButtonListener);
//Show list Button
buttonShow = new JButton("Show list");
buttonShow.setBounds(100, 90, 100, 25);
panel.add(buttonShow);
ShowButtonListener showButtonListener = new ShowButtonListener();
buttonShow.addActionListener(showButtonListener);
//Login successful
success = new JLabel("");
success.setBounds(100, 110, 300, 25);
panel.add(success);
//Panel visible
frame.setVisible(true);
}
//ActionListener for register
public static class RegisterButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
user = userText.getText();
pass = passwordText.getText();
listUser = new DataUser(user, pass);
array.add(listUser);
System.out.println(array);
success.setText("Registration added!");
}
}
//ActionListener for show list
public static class ShowButtonListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
//show = new Show();(This was the problem)
show.setUser(user);
show.setPass(pass);
show.saveData();
show.setVisible(true);
}
}
}
DataUser:
public class DataUser {
private final String user;
private final String pass;
private final String breakLine = "";
public DataUser(String user, String pass) {
this.user = user;
this.pass = pass;
}
#Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(breakLine).append(System.getProperty("line.separator"));
return "User: " + user + " | Pass: " + pass
+ sb.toString();
}
}
And the new JFrame where is the JTable: JTable
Code (Problem is probably in the saveData() method):
import javax.swing.table.DefaultTableModel;
public final class Show extends javax.swing.JFrame {
DefaultTableModel table;
private final String[][] matrix = {};
String head[] = {"User", "Pass"};
private String user, pass;
public Show() {
initComponents();
table = new DefaultTableModel(matrix, head);
jTable.setModel(table);
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
public void saveData() { //Problem is probably here
String data[] = {getUser(), getPass()};
table.addRow(data);
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
jTable1 = new javax.swing.JTable();
jButton1 = new javax.swing.JButton();
jScrollPane2 = new javax.swing.JScrollPane();
jTable = new javax.swing.JTable();
jTable1.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
{null, null}
},
new String [] {
"User", "Pass"
}
));
jScrollPane1.setViewportView(jTable1);
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jButton1.setText("<- Return");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});
jTable.setModel(new javax.swing.table.DefaultTableModel(
new Object [][] {
},
new String [] {
"Title1", "Title2"
}
) {
boolean[] canEdit = new boolean [] {
false, false
};
public boolean isCellEditable(int rowIndex, int columnIndex) {
return canEdit [columnIndex];
}
});
jScrollPane2.setViewportView(jTable);
if (jTable.getColumnModel().getColumnCount() > 0) {
jTable.getColumnModel().getColumn(0).setResizable(false);
jTable.getColumnModel().getColumn(1).setResizable(false);
}
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addComponent(jButton1)
.addGap(0, 0, Short.MAX_VALUE))
.addComponent(jScrollPane2, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 376, Short.MAX_VALUE))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 275, Short.MAX_VALUE)
.addContainerGap())
);
pack();
}// </editor-fold>
//Return Button
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
dispose();
}
public static void main(String args[]) {
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Show.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Show.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Show.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Show.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(() -> {
new Show().setVisible(true);
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTable jTable;
private javax.swing.JTable jTable1;
// End of variables declaration
}

Run file not updating changes in GUI using Swing

I'm doing a login screen with Swing. I edited the enable property of the only button that exists in the screen - the "Entrar", as shown in the picture below:
Login screen
But, when I hit Shift-F6 (Run file) it doesn't shows the change:
Login Screen after running single file
Here's the code:
package view;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
/**
*
* #author User
*/
public class Inicio extends javax.swing.JFrame {
String usuario;
String senha;
int a;
public Inicio() {
initComponents();
DocumentListener dUsuario = new DocumentListener(){
#Override
public void insertUpdate(DocumentEvent e) {
try {
usuario = e.getDocument().getText(0, 0);
a = 1;
} catch (BadLocationException ex) {
Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
}
}
#Override
public void removeUpdate(DocumentEvent e) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
#Override
public void changedUpdate(DocumentEvent e) {
try {
usuario = e.getDocument().getText(0, 0);
a = 1;
} catch (BadLocationException ex) {
Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
}
}
};
DocumentListener dSenha = new DocumentListener(){
#Override
public void insertUpdate(DocumentEvent e) {
try {
senha = e.getDocument().getText(0, 0);
a = 2;
} catch (BadLocationException ex) {
Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
}
}
#Override
public void removeUpdate(DocumentEvent e) {
throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
}
#Override
public void changedUpdate(DocumentEvent e) {
try {
senha = e.getDocument().getText(0, 0);
a = 2;
} catch (BadLocationException ex) {
Logger.getLogger(Inicio.class.getName()).log(Level.SEVERE, null, ex);
}
}
};
tUsuario.getDocument().addDocumentListener(dUsuario);
tSenha.getDocument().addDocumentListener(dSenha);
if(a == 2) {
if (bEntrar.isEnabled() == false) {
bEntrar.setEnabled(true);
}
}else{
if (bEntrar.isEnabled() == true) {
bEntrar.setEnabled(false);
}
}
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
tSenha = new javax.swing.JPasswordField();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
tUsuario = new javax.swing.JFormattedTextField();
bEntrar = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setResizable(false);
jLabel1.setForeground(new java.awt.Color(153, 153, 153));
jLabel1.setText("Informe apenas os dígitos do CPF.");
jLabel2.setText("Senha:");
jLabel3.setText("CPF:");
jLabel4.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
jLabel4.setText("LOGIN");
try {
tUsuario.setFormatterFactory(new javax.swing.text.DefaultFormatterFactory(new javax.swing.text.MaskFormatter("###.###.###-##")));
} catch (java.text.ParseException ex) {
ex.printStackTrace();
}
bEntrar.setText("Entrar");
bEntrar.setEnabled(false);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(184, 184, 184)
.addComponent(jLabel4)
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 91, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel3, javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(jLabel2, javax.swing.GroupLayout.Alignment.TRAILING))
.addGap(7, 7, 7)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel1)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(tSenha, javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(bEntrar, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, 129, Short.MAX_VALUE))
.addComponent(tUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, 128, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(55, 55, 55))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(50, 50, 50)
.addComponent(jLabel4)
.addGap(37, 37, 37)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(tUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(3, 3, 3)
.addComponent(jLabel1)
.addGap(9, 9, 9)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel2)
.addComponent(tSenha, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 58, Short.MAX_VALUE)
.addComponent(bEntrar)
.addGap(41, 41, 41))
);
pack();
}// </editor-fold>
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Inicio.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Inicio().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton bEntrar;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JPasswordField tSenha;
private javax.swing.JFormattedTextField tUsuario;
// End of variables declaration
}
I edited the button properties using the Project view from Swing. So, what can I do to fix that? Is it a Netbeans bug? I'm using Netbeans IDE 8.2, by the way.

If you want to effect the state of the button based on changes which have occurred on the text fields, then those actions need to take place in the action handlers themselves (ie, the DocumentListeners)
The following is a very basic example, which disables the "action" button until both the user name and password fields are no longer empty
import java.awt.EventQueue;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private JTextField userNameField;
private JPasswordField passwordField;
private JButton actionButton;
public TestPane() {
userNameField = new JTextField(15);
passwordField = new JPasswordField(15);
actionButton = new JButton("Do stuff");
actionButton.setEnabled(false);
DocumentListener documentListener = new DocumentListener() {
protected void stateDidChange() {
actionButton.setEnabled(userNameField.getText().length() > 0 && passwordField.getPassword().length > 0);
}
#Override
public void insertUpdate(DocumentEvent e) {
stateDidChange();
}
#Override
public void removeUpdate(DocumentEvent e) {
stateDidChange();
}
#Override
public void changedUpdate(DocumentEvent e) {
stateDidChange();
}
};
userNameField.getDocument().addDocumentListener(documentListener);
passwordField.getDocument().addDocumentListener(documentListener);
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
gbc.gridwidth = gbc.REMAINDER;
add(userNameField, gbc);
add(passwordField, gbc);
add(actionButton, gbc);
}
}
}
Why is the initial state not been updated?
You define a as....
int a;
which gives it a initial (or default) value of 0.
You then use...
if(a == 2) {
if (bEntrar.isEnabled() == false) {
bEntrar.setEnabled(true);
}
}else{
if (bEntrar.isEnabled() == true) {
bEntrar.setEnabled(false);
}
}
to change the initial state. Since a is 0, the else block is executed, the only condition which would change the button enabled state to false would be if the current enabled state is true
But when I use Shift+F6 to run the code it doesn't work
Do a "clean and build" and run the project, not the file. In testing your code, the UI appears with the button already disabled

Unable to drag and drop sometimes

package newjframe;
import java.awt.BorderLayout;
import java.awt.Cursor;
import java.awt.Point;
import java.awt.event.MouseEvent;
import javax.swing.JComponent;
import javax.swing.event.MouseInputAdapter;
public class NewJFrame extends javax.swing.JFrame {
public NewJFrame() {
initComponents();
setLocationRelativeTo(null);
}
public class Draggable extends JComponent {
private Point pointPressed;
private JComponent draggable;
public Draggable(final JComponent component, final int x, final int y) {
draggable = component;
setCursor(new Cursor(Cursor.HAND_CURSOR));
setLocation(x, y);
setSize(component.getPreferredSize());
setLayout(new BorderLayout());
add(component);
MouseInputAdapter mouseAdapter = new MouseHandler();
addMouseMotionListener(mouseAdapter);
addMouseListener(mouseAdapter);
}
public class MouseHandler extends MouseInputAdapter {
#Override
public void mouseDragged(final MouseEvent e) {
Point pointDragged = e.getPoint();
Point location = getLocation();
location.translate(pointDragged.x - pointPressed.x,
pointDragged.y - pointPressed.y);
setLocation(location);
}
#Override
public void mousePressed(final MouseEvent e) {
pointPressed = e.getPoint();
}
}
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
panel = new javax.swing.JPanel();
layer = new javax.swing.JLayeredPane();
cbb = new javax.swing.JComboBox<>();
label = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
cbb.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "Item 1", "Item 2", "Item 3"}));
cbb.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
cbbActionPerformed(evt);
}
});
layer.setLayer(cbb, javax.swing.JLayeredPane.DEFAULT_LAYER);
layer.setLayer(label, javax.swing.JLayeredPane.DEFAULT_LAYER);
javax.swing.GroupLayout layerLayout = new javax.swing.GroupLayout(layer);
layer.setLayout(layerLayout);
layerLayout.setHorizontalGroup(
layerLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layerLayout.createSequentialGroup()
.addGap(41, 41, 41)
.addComponent(cbb, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(129, 129, 129)
.addComponent(label)
.addContainerGap(202, Short.MAX_VALUE))
);
layerLayout.setVerticalGroup(
layerLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layerLayout.createSequentialGroup()
.addGap(30, 30, 30)
.addGroup(layerLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
.addComponent(label)
.addComponent(cbb, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addContainerGap(329, Short.MAX_VALUE))
);
javax.swing.GroupLayout panelLayout = new javax.swing.GroupLayout(panel);
panel.setLayout(panelLayout);
panelLayout.setHorizontalGroup(
panelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(layer)
);
panelLayout.setVerticalGroup(
panelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(layer)
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(panel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(panel, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
private void cbbActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
int[] xy = {100, 200, 300};
label.setText("DRAG THIS");
switch (cbb.getSelectedIndex()) {
case 0:
draglabel = new Draggable(label, xy[0], xy[0]);
layer.add(draglabel);
break;
case 1:
draglabel = new Draggable(label, xy[0], xy[1]);
layer.add(draglabel);
break;
case 2:
draglabel = new Draggable(label, xy[0], xy[2]);
layer.add(draglabel);
break;
default:
draglabel = new Draggable(label, xy[0], xy[0]);
layer.add(draglabel);
}
}
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new NewJFrame().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JComboBox<String> cbb;
private javax.swing.JLabel label;
private javax.swing.JLayeredPane layer;
private javax.swing.JPanel panel;
// End of variables declaration
Draggable draglabel;
}
The above code should allow the Jlabels to be dragged and dropped with ease, but every time they're called with the actionlistener in JComboBox, they become harder to drag and drop. GIF added to for better clarity https://imgur.com/rPL5ZMC I have tried repaint() method in the class method, and actionlistner but it didn't work

Again, I would tend to simplify try to clarify things, including:
Use the much simpler MouseListener/MouseAdapter and not D&D as you initially were doing. You appear to have made this change.
Not wrapping the JLabel unnecessarily in another component
Thus the Mouse listeners would be added directly on the JLabel and not on a wrapper object.
Not changing the JLayeredPane's default and unique layout
Explicitly removing the old components before adding new ones
Calling repaint() on the JLayeredPane after adding or removing components.
For example, something like this:
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class TestDragging extends JPanel {
private static final String[] ITEMS = {"Item One", "Item Two", "Item Three"};
private static final Dimension PREF_SIZE = new Dimension(400, 400);
private JLabel label;
private JComboBox<String> comboBox = new JComboBox<>(ITEMS);
private JLayeredPane layeredPane = new JLayeredPane();
public TestDragging() {
comboBox.addActionListener(new ComboListener());
JPanel topPanel = new JPanel();
topPanel.add(comboBox);
layeredPane.setPreferredSize(PREF_SIZE);
layeredPane.setBorder(BorderFactory.createEtchedBorder());
setLayout(new BorderLayout());
add(topPanel, BorderLayout.PAGE_START);
add(layeredPane, BorderLayout.CENTER);
}
private class ComboListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (label != null) {
layeredPane.remove(label);
}
int index = comboBox.getSelectedIndex();
int x = 100;
int y = 100 + 100 * index;
String text = comboBox.getSelectedItem().toString();
label = createDraggingLabel(x, y, text);
layeredPane.add(label, JLayeredPane.DEFAULT_LAYER);
layeredPane.repaint();
}
private JLabel createDraggingLabel(int x, int y, String text) {
JLabel label = new JLabel(text);
label.setSize(label.getPreferredSize());
label.setLocation(x, y);
MyMouse myMouse = new MyMouse();
label.addMouseListener(myMouse);
label.addMouseMotionListener(myMouse);
return label;
}
}
private static void createAndShowGui() {
TestDragging mainPanel = new TestDragging();
JFrame frame = new JFrame("Test Dragging");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class MyMouse extends MouseAdapter {
private Point pointPressed = null;
#Override
public void mousePressed(MouseEvent e) {
pointPressed = e.getPoint();
}
#Override
public void mouseDragged(MouseEvent e) {
JLabel label = (JLabel) e.getSource();
label.setCursor(new Cursor(Cursor.HAND_CURSOR));
Point pointDragged = e.getPoint();
Point location = label.getLocation();
int dx = pointDragged.x - pointPressed.x;
int dy = pointDragged.y - pointPressed.y;
location.translate(dx, dy);
label.setLocation(location);
Container container = label.getParent();
container.repaint();
}
}

I've called and instantiated the drag n drop function in the constructor then I've used label.setLocation(x, y) to solve this problem since the JComboBox merely determines the position of the labels, I do not need to have re-instantiate the object every time actionperformed is called.

Calling a JPanel from within a JPanel that resides in a JFrame - in netbeans

(Edited)
I'm creating a small project with dynamically changing panels.
I've been able to write code that can call a JPanel using an action event from a button within the the JFrame (ManagerScreen). For example:
package route66.JFrames;
import route66.pannels.BuyReserve;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import route66.pannels.Buy;
import route66.pannels.BuyReport;
import route66.pannels.CustomerDetails;
import route66.pannels.NewUser;
import route66.pannels.QuotPanel;
import route66.pannels.ReportPanel;
import route66.pannels.Salaries_Com;
import route66.pannels.SaleSucces;
/**
*
* #author Vavu
*/
public class ManagerScreen extends javax.swing.JFrame {
GridBagLayout layout = new GridBagLayout();
Buy BuyPanel = new Buy();
Buy b = new Buy();
BuyReserve buyR = new BuyReserve();
BuyReport brep = new BuyReport();
CustomerDetails cusD = new CustomerDetails();
QuotPanel QP = new QuotPanel();
ReportPanel RP = new ReportPanel();
NewUser NW = new NewUser();
Salaries_Com SalCom = new Salaries_Com();
SaleSucces SalS = new SaleSucces();
boolean visible;
/**
* Creates new form ManagerScreen
* #param pabel
*/
public ManagerScreen() {
initComponents();
DynamicPanel.setLayout(layout);
GridBagConstraints c = new GridBagConstraints();
c.gridx = 0;
c.gridy = 0;
DynamicPanel.add(b,c);
DynamicPanel.add(buyR,c);
DynamicPanel.add(brep,c);
DynamicPanel.add(cusD,c);
DynamicPanel.add(QP,c);
DynamicPanel.add(RP,c);
DynamicPanel.add(NW,c);
DynamicPanel.add(SalCom,c);
DynamicPanel.add(SalS,c);
b.setVisible(false);
buyR.setVisible(false);
brep.setVisible(false);
cusD.setVisible(false);
QP.setVisible(false);
RP.setVisible(false);
NW.setVisible(false);
SalCom.setVisible(false);
SalS.setVisible(false);
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
DynamicPanel = new javax.swing.JPanel();
MSbuy = new javax.swing.JButton();
MSQuotation = new javax.swing.JButton();
MSReserve = new javax.swing.JButton();
MSSalCom = new javax.swing.JButton();
MSReport = new javax.swing.JButton();
MSCreateNew = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setMinimumSize(new java.awt.Dimension(980, 740));
getContentPane().setLayout(null);
DynamicPanel.setBackground(new java.awt.Color(255, 0, 0));
DynamicPanel.setMaximumSize(new java.awt.Dimension(500, 500));
DynamicPanel.setMinimumSize(new java.awt.Dimension(500, 500));
DynamicPanel.setPreferredSize(new java.awt.Dimension(700, 500));
javax.swing.GroupLayout DynamicPanelLayout = new javax.swing.GroupLayout(DynamicPanel);
DynamicPanel.setLayout(DynamicPanelLayout);
DynamicPanelLayout.setHorizontalGroup(
DynamicPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 700, Short.MAX_VALUE)
);
DynamicPanelLayout.setVerticalGroup(
DynamicPanelLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 500, Short.MAX_VALUE)
);
getContentPane().add(DynamicPanel);
DynamicPanel.setBounds(330, 260, 700, 500);
MSbuy.setText("Buy");
MSbuy.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSbuyActionPerformed(evt);
}
});
getContentPane().add(MSbuy);
MSbuy.setBounds(70, 480, 188, 29);
MSQuotation.setText("Quotation");
MSQuotation.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSQuotationActionPerformed(evt);
}
});
getContentPane().add(MSQuotation);
MSQuotation.setBounds(70, 520, 188, 29);
MSReserve.setText("Reserve");
MSReserve.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSReserveActionPerformed(evt);
}
});
getContentPane().add(MSReserve);
MSReserve.setBounds(70, 440, 188, 29);
MSSalCom.setText("Salaries & Commission");
MSSalCom.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSSalComActionPerformed(evt);
}
});
getContentPane().add(MSSalCom);
MSSalCom.setBounds(70, 400, 188, 29);
MSReport.setText("Report");
MSReport.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSReportActionPerformed(evt);
}
});
getContentPane().add(MSReport);
MSReport.setBounds(70, 560, 187, 29);
MSCreateNew.setText("Create New User");
MSCreateNew.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
MSCreateNewActionPerformed(evt);
}
});
getContentPane().add(MSCreateNew);
MSCreateNew.setBounds(70, 600, 187, 29);
jLabel1.setFont(new java.awt.Font("Lucida Grande", 0, 48)); // NOI18N
jLabel1.setForeground(new java.awt.Color(0, 0, 204));
jLabel1.setText("ROUTE66 CAR DEALERSHIP");
getContentPane().add(jLabel1);
jLabel1.setBounds(330, 0, 650, 130);
jLabel3.setText(".");
getContentPane().add(jLabel3);
jLabel3.setBounds(0, 0, 330, 260);
jLabel2.setText(".");
getContentPane().add(jLabel2);
jLabel2.setBounds(330, 90, 650, 210);
pack();
}// </editor-fold>
private void MSbuyActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
b.setVisible(false);
buyR.setVisible(true);
brep.setVisible(false);
cusD.setVisible(false);
QP.setVisible(false);
RP.setVisible(false);
NW.setVisible(false);
SalCom.setVisible(false);
SalS.setVisible(false);
}
private void MSSalComActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
b.setVisible(false);
buyR.setVisible(false);
brep.setVisible(false);
cusD.setVisible(false);
QP.setVisible(false);
RP.setVisible(false);
NW.setVisible(false);
SalCom.setVisible(true);
SalS.setVisible(false);
}
private void MSReserveActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
b.setVisible(false);
buyR.setVisible(false);
brep.setVisible(false);
cusD.setVisible(false);
QP.setVisible(false);
RP.setVisible(true);
NW.setVisible(false);
SalCom.setVisible(false);
SalS.setVisible(false);
}
private void MSQuotationActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void MSReportActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
private void MSCreateNewActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(ManagerScreen.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ManagerScreen.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ManagerScreen.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ManagerScreen.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new ManagerScreen().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel DynamicPanel;
private javax.swing.JButton MSCreateNew;
private javax.swing.JButton MSQuotation;
private javax.swing.JButton MSReport;
private javax.swing.JButton MSReserve;
private javax.swing.JButton MSSalCom;
private javax.swing.JButton MSbuy;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
// End of variables declaration
}
My problem is that the BR panel (buyReserve()), containing two buttons - within the JFrame, is supposed to be able to call either the buy panel or brep panel (BuyReport()) from the within the DynamicPanel() or at least thats what I think, if that makes sense.
so basically I've tried somethings including the following:
package route66.pannels;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import route66.pannels.BuyReport;
import route66.pannels.CustomerDetails;
/**
*
* #author Vavu
*/
public class BuyReserve extends javax.swing.JPanel {
GridBagLayout layout = new GridBagLayout();
Buy BuyPanel = new Buy();
Buy b = new Buy();
BuyReserve buyR = new BuyReserve();
BuyReport brep = new BuyReport();
CustomerDetails cusD = new CustomerDetails();
QuotPanel QP = new QuotPanel();
ReportPanel RP = new ReportPanel();
NewUser NW = new NewUser();
Salaries_Com SalCom = new Salaries_Com();
SaleSucces SalS = new SaleSucces();
/**
* Creates new form BuyReserve
*/
public BuyReserve() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
btnBuy = new javax.swing.JButton();
btnReserve = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
btnBuy.setText("New Client");
btnBuy.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnBuyActionPerformed(evt);
}
});
btnReserve.setText("Reserve Client");
jLabel1.setText("Select Option");
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);
this.setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(144, 144, 144)
.addComponent(btnBuy)
.addGap(35, 35, 35)
.addComponent(btnReserve))
.addGroup(layout.createSequentialGroup()
.addGap(230, 230, 230)
.addComponent(jLabel1)))
.addContainerGap(162, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(62, 62, 62)
.addComponent(jLabel1)
.addGap(72, 72, 72)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(btnBuy)
.addComponent(btnReserve))
.addContainerGap(201, Short.MAX_VALUE))
);
}// </editor-fold>
private void btnBuyActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
b.setVisible(true);
}
// Variables declaration - do not modify
private javax.swing.JButton btnBuy;
private javax.swing.JButton btnReserve;
private javax.swing.JLabel jLabel1;
// End of variables declaration
}
If I run the ManagerScreen with the inclusion of the second code snippet I get an error. I've also tried other types of code that end up saying things like the jpanel doesn't have a main class n so on.
So, hopefully by this stage I've been able to get my point across to be to able ask (again); how do I call a panel, within a panel that is inside a JFrame?

You state that you want to "call" JPanels, but this doesn't really have any meaning. If your goal is to swap JPanel views, then the simplest and easiest way is to use a CardLayout. For more on this useful tool, please see the CardLayout Tutorial.
For example:
import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import javax.swing.*;
public class ManagerPanel extends JPanel {
private CardLayout cardLayout = new CardLayout();
private JPanel cardLayoutPanel = new JPanel(cardLayout);
private BuyPanel buyPanel = new BuyPanel(this);
private BuyReportPanel buyReportPanel = new BuyReportPanel(this);
private DefaultComboBoxModel<String> comboModel = new DefaultComboBoxModel<>();
private JComboBox<String> panelComboBox = new JComboBox<>(comboModel);
public ManagerPanel() {
comboModel.addElement(BuyPanel.BUY);
comboModel.addElement(BuyReportPanel.BUY_REPORT);
panelComboBox.addActionListener(evt -> {
String key = panelComboBox.getSelectedItem().toString();
cardLayout.show(cardLayoutPanel, key);
});
JPanel comboPanel = new JPanel();
comboPanel.add(panelComboBox);
cardLayoutPanel.add(buyPanel, BuyPanel.BUY);
cardLayoutPanel.add(buyReportPanel, BuyReportPanel.BUY_REPORT);
setLayout(new BorderLayout());
add(cardLayoutPanel, BorderLayout.CENTER);
add(comboPanel, BorderLayout.PAGE_END);
}
private static void createAndShowGui() {
ManagerPanel mainPanel = new ManagerPanel();
JFrame frame = new JFrame("ManagerPanel");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
public void nextPanel() {
cardLayout.next(cardLayoutPanel);
}
}
class BuyReportPanel extends JPanel {
public final static String BUY_REPORT = "Buy Report";
private ManagerPanel managerPanel;
public BuyReportPanel(ManagerPanel managerPanel) {
this.managerPanel = managerPanel;
add(new JLabel(BUY_REPORT), SwingConstants.CENTER);
add(new JButton(new NextPanelAction(managerPanel)));
}
}
class BuyPanel extends JPanel {
public final static String BUY = "Buy";
private ManagerPanel managerPanel;
public BuyPanel(ManagerPanel managerPanel) {
setPreferredSize(new Dimension(400, 300));
this.managerPanel = managerPanel;
add(new JLabel(BUY), SwingConstants.CENTER);
add(new JButton(new NextPanelAction(managerPanel)));
}
}
class NextPanelAction extends AbstractAction {
private ManagerPanel managerPanel;
public NextPanelAction(ManagerPanel managerPanel) {
super("Next Panel");
this.managerPanel = managerPanel;
}
#Override
public void actionPerformed(ActionEvent e) {
managerPanel.nextPanel();
}
}
Note that I've passed my main class, here ManagerPanel, into other classes, and so they can call any of its public methods including nextPanel(), as needed.

Java Hidden JTabbedPane

I want when I click on tab1 or tab2. Japel display will hide or show,I want the results shown in Figure 2.I use the command jPanel2.setPreferredSize(new Dimension(0, 0));
Ex: If I have 10,I need setPreferredSize for 10 japanel with each tab.I want to ask a much easier way.
Events to click on my tab does not work properly.Please help me
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package main;
import java.awt.Dimension;
/**
*
* #author KhongTuyen
*/
public class demo extends javax.swing.JFrame {
/**
* Creates new form demo
*/
public demo() {
initComponents();
jPanel2.setVisible(false);
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jTabbedPane1 = new javax.swing.JTabbedPane();
jPanel4 = new javax.swing.JPanel();
jPanel1 = new javax.swing.JPanel();
jPanel2 = new javax.swing.JPanel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jTabbedPane1.setTabPlacement(javax.swing.JTabbedPane.BOTTOM);
jTabbedPane1.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jTabbedPane1MouseClicked(evt);
}
});
jTabbedPane1.addChangeListener(new javax.swing.event.ChangeListener() {
public void stateChanged(javax.swing.event.ChangeEvent evt) {
jTabbedPane1StateChanged(evt);
}
});
jPanel4.setPreferredSize(new java.awt.Dimension(395, 0));
javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
jPanel4.setLayout(jPanel4Layout);
jPanel4Layout.setHorizontalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 395, Short.MAX_VALUE)
);
jPanel4Layout.setVerticalGroup(
jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 0, Short.MAX_VALUE)
);
jTabbedPane1.addTab("tab1", jPanel4);
jPanel1.setPreferredSize(new java.awt.Dimension(395, 0));
javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 395, Short.MAX_VALUE)
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 0, Short.MAX_VALUE)
);
jTabbedPane1.addTab("tab2", jPanel1);
getContentPane().add(jTabbedPane1, java.awt.BorderLayout.PAGE_START);
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 253, Short.MAX_VALUE)
);
getContentPane().add(jPanel2, java.awt.BorderLayout.CENTER);
pack();
}// </editor-fold>
private void jTabbedPane1MouseClicked(java.awt.event.MouseEvent evt) {
int count = 0;
if (count % 2 != 0) {
jPanel2.setPreferredSize(new Dimension(0, 100));
jPanel1.setPreferredSize(new Dimension(0, 100));
} else {
jPanel2.setPreferredSize(new Dimension(0, 0));
jPanel1.setPreferredSize(new Dimension(0, 0));
}
count++;
}
private void jTabbedPane1StateChanged(javax.swing.event.ChangeEvent evt) {
// TODO add your handling code here:
}
/**
* #param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(demo.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(demo.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(demo.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(demo.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new demo().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel4;
private javax.swing.JTabbedPane jTabbedPane1;
// End of variables declaration
}

Use a JSplitPane. You can click on a button on the divider to have the divider go to the minimum or maximum value of the divider.
However, in order for the divider to go to the minimum the getMinimumSize() method must return a Dimension of (0, 0).
Read the section from the Swing tutorial on How to Use Split Panes for more information and examples.

Did you mean something like this
import java.awt.BorderLayout;
import java.awt.Font;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.JTextField;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class TabSample {
static void add(JTabbedPane tabbedPane, String text) {
String text1 = "";
JPanel panel = new JPanel();
if (text.equals("tab1")){
text1 = "";
}
else
{
text1 = text;
}
JLabel label = new JLabel(text1);
label.setFont(new Font(null,Font.BOLD,30));
label.setText(text1);
panel.add(label);
tabbedPane.addTab(text,label);
}
public static void main(String args[]) {
JFrame frame = new JFrame("Tabbed Pane Sample");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JTabbedPane tabbedPane = new JTabbedPane();
tabbedPane.setTabPlacement(JTabbedPane.BOTTOM);
String titles[] = { "tab1", "Jpanel Display 2"};
for (int i = 0, n = titles.length; i < n; i++) {
add(tabbedPane, titles[i]);
}
ChangeListener changeListener = new ChangeListener() {
public void stateChanged(ChangeEvent changeEvent) {
JTabbedPane sourceTabbedPane = (JTabbedPane) changeEvent.getSource();
int index = sourceTabbedPane.getSelectedIndex();
System.out.println("Tab changed to: " + sourceTabbedPane.getTitleAt(index));
}
};
tabbedPane.addChangeListener(changeListener);
frame.add(tabbedPane, BorderLayout.CENTER);
frame.setSize(400, 150);
frame.setVisible(true);
}
}