Hi there mate...

I had tried to solve your question, but somehow this Combo Box seems like not reacting to the user events that nicely. Once you select a certain value
for one combo box ,, you need to click the combobox again to let that value pass onto the second combobox. But hope that might solve your problem.
If the problem persists, please do refer me back. Hope i can be of some help.

The Code is used is this :

import javax.swing.*;
import java.awt.event.*;

public class TestCombo implements MouseListener{

private JFrame frame;
private JPanel panel;
private JComboBox cBox1;
private JComboBox cBox2;

public TestCombo() {

frame = new JFrame("Combo Test : ");
frame.setDefaultCloseOperation(frame.EXIT_ON_CLOSE);
panel = new JPanel();
cBox1 = new JComboBox();
cBox2 = new JComboBox();

cBox1.addMouseListener(this);
cBox2.addMouseListener(this);
}

public void launchApp() {

frame.add(panel);

for (int count = 0; count < 5; count++)
cBox1.addItem(Integer.toString(count));

for (int count = 0; count < 5; count++)
cBox2.addItem(Integer.toString(count));

panel.add(cBox1);
panel.add(cBox2);

frame.pack();
frame.setVisible(true);
}

public void mouseClicked(MouseEvent me) {

JComboBox cBox = (JComboBox)me.getSource();

if (cBox == cBox1) {

frame.setVisible(false);
frame.remove(panel);
cBox2.setSelectedItem(cBox1.getSelectedItem());
frame.add(panel);
frame.setVisible(true);
}
else if (cBox == cBox2) {

frame.setVisible(false);
cBox1.setSelectedItem(cBox2.getSelectedItem());
frame.setVisible(true);
}
}

public void mouseReleased(MouseEvent me) {
}

public void mouseEntered(MouseEvent me) {
}

public void mouseExited(MouseEvent me) {
}

public void mousePressed(MouseEvent me) {
}

public static void main(String[] args) {

TestCombo tc = new TestCombo();
tc.launchApp();
}
}

Hi Friend,

Try the following code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Compare extends JFrame implements ItemListener{
JComboBox combo,lcombo;

public Compare(){
setLayout(null);
String a[]={"Select","Watches","Mobiles","shoes"};
combo=new JComboBox(a);combo.setBounds(50,50,100,20);
combo.addItemListener(this);
add(combo);

lcombo=new JComboBox();
lcombo.addItemListener(this);lcombo.setEnabled(false);
add(lcombo);lcombo.setBounds(50,100,100,20);

setSize(300,300);
}

public void itemStateChanged(ItemEvent e) {
String b[]={"Select","Titan","HMT"};
String c[]={"Select","Nokia","Sony","Motorola","Samsung"};
String d[]={"Select","Liberty","Action","Bata","Campus","Relaxo"};

if(e.getSource() == combo) {
if(combo.getSelectedItem().equals("Select")){
lcombo.setEnabled(false);
}
else if(combo.getSelectedItem().equals("Watches")){
lcombo.setEnabled(true);
lcombo.removeAllItems();
for(int i=0;i<b.length;i++){
lcombo.addItem(b[i]);
}
}
else if(combo.getSelectedItem().equals("Mobiles"))
{
lcombo.setEnabled(true);
lcombo.removeAllItems();
for(int i=0;i<c.length;i++){
lcombo.removeItem(c[i]);
lcombo.addItem(c[i]);
}
}
else if(combo.getSelectedItem().equals("shoes")){
lcombo.setEnabled(true);
lcombo.removeAllItems();
for(int i=0;i<d.length;i++){
lcombo.addItem(d[i]);
}
}
}
}
public static void main(String args[])
{
(new Compare()).setVisible(true);
}
}

Thanks