Question

I have a netbeans Java application that should display a JFrame (class StartUpWindow extends JFrame) with some options when the application is launched, then the user clicks a button and that JFrame should be closed and a new one (class MainWindow) should be opened.

So how do I do this correctly. I obviously set a click handler on the button in StartupWindow but what do I put in this handler so that I can close the StartUpWindow and open the MainWindow? It seems that threading comes into this too as every window seems to have their own thread…or are threading issues automatically handled by JFrames themselves…

Answer 1

Here is an example:

StartupWindow.java

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;


public class StartupWindow extends JFrame implements ActionListener
{
    private JButton btn;

    public StartupWindow()
    {
        super("Simple GUI");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        btn = new JButton("Open the other JFrame!");
        btn.addActionListener(this);
        btn.setActionCommand("Open");
        add(btn);
        pack();

    }

    @Override
    public void actionPerformed(ActionEvent e)
    {
        String cmd = e.getActionCommand();

        if(cmd.equals("Open"))
        {
            dispose();
            new AnotherJFrame();
        }
    }

    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable(){

            @Override
            public void run()
            {
                new StartupWindow().setVisible(true);
            }

        });
    }
}

AnotherJFrame.java

import javax.swing.JFrame;
import javax.swing.JLabel;

public class AnotherJFrame extends JFrame
{
    public AnotherJFrame()
    {
        super("Another GUI");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        add(new JLabel("Empty JFrame"));
        pack();
        setVisible(true);
    }
}