Dynamic JComboBoxes?

I have following data (String):

Course1: A1
Course1: A2
Course2: B1
Course2: B2
Course2: B3
Course2: B4
Course3: C1
Course3: C2
I’d like to create two JComboBox (JComboBox1, JComboBox2) so that JComboBox1 contains Course1,Course2,Course3, etc.

If I select, say, Course2 from JComboBox1 then corresponding B1,B2,B3,B4 should be populated in JComboBox2.

Yes, simply create a DefaultComboBoxModel for each set, and do setModel() on JComboBox2 when JComboBox1 changes.

Addendum: For example,

 

import java.awt.EventQueue;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.ComboBoxModel;

import javax.swing.DefaultComboBoxModel;

import javax.swing.JComboBox;

import javax.swing.JFrame;

import javax.swing.JPanel;

 

public class ComboTest extends JPanel implements ActionListener, Runnable {

 

    private final JComboBox combo1 = new JComboBox(

        new String[]{"Course 1", "Course 2", "Course 3"});

    private final JComboBox combo2 = new JComboBox();

    private ComboBoxModel[] models = new ComboBoxModel[3];

 

    public ComboTest() {

        models[0] = new DefaultComboBoxModel(

            new String[]{"A1", "A2"});

        models[1] = new DefaultComboBoxModel(

            new String[]{"B1", "B2", "B3", "B4"});

        models[2] = new DefaultComboBoxModel(

            new String[]{"C1", "C2"});

 

        combo2.setModel(models[0]);

        this.add(combo1);

        this.add(combo2);

        combo1.addActionListener(this);

    }

 

    @Override

    public void actionPerformed(ActionEvent e) {

    int i = combo1.getSelectedIndex();

    combo2.setModel(models[i]);

    }

 

    @Override

    public void run() {

        JFrame f = new JFrame("ComboTest");

        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        f.add(this);

        f.pack();

        f.setLocationRelativeTo(null);

        f.setVisible(true);

    }

 

    public static void main(String[] args) {

        EventQueue.invokeLater(new ComboTest());

    }

}