Java swing应用程序，单击按钮时关闭一个窗口，然后打开另一个窗口

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);    }}