Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.awt.FlowLayout;

import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;

public class Main {
    public static void main(String args[]) {
        String[] mainData = { "-Select-", "Sel 1", "Sel 2", "Sel 3" };
        String[] subData1 = { "Sub Sel 11", "Sub Sel 12", "Sub Sel 13" };
        String[] subData2 = { "Sub Sel 21", "Sub Sel 22", "Sub Sel 23" };
        String[] subData3 = { "Sub Sel 31", "Sub Sel 32", "Sub Sel 33" };
        DefaultComboBoxModel boxModel = new DefaultComboBoxModel();
        JComboBox box1 = new JComboBox(mainData), box2 = new JComboBox();
        JFrame frame = new JFrame();
        frame.setLayout(new FlowLayout());
        frame.add(box1);
        frame.add(box2);
        box2.setVisible(false);
        box2.setModel(boxModel);
        frame.setBounds(200, 200, 500, 200);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

        box1.addItemListener(e -> {
            box2.setVisible(true);
            boxModel.removeAllElements();
            if (box1.getSelectedIndex() == 0) {
                box2.setVisible(false);
            } else if (box1.getSelectedIndex() == 1) {
                for (String s : subData1) {
                    boxModel.addElement(s);
                }
            } else if (box1.getSelectedIndex() == 2) {
                for (String s : subData2) {
                    boxModel.addElement(s);
                }
            } else if (box1.getSelectedIndex() == 3) {
                for (String s : subData3) {
                    boxModel.addElement(s);
                }
            }
        });
    }
}