私と友人は、Javaのボタンを備えたmp3プレーヤーを作成しようとしていますが、最初のボタンをクリックすると、2番目のメニューのすべてのボタンのサイズが変更されます。ボタンがサイズ変更されないようにする方法についての情報をいただければ幸いです。
    import java.awt.event.*;
       import javax.swing.*;
       import java.awt.*;
   public class Player extends JFrame {
  class CustomPanel extends JPanel{     //create image
     public void paintComponent (Graphics painter){
        Image pic = Toolkit.getDefaultToolkit().getImage("playerBase.jpg");
        if(pic != null) painter.drawImage(pic, 0, 0, this);
     }
  }
  public static void main(String[] args) {
     Player gui = new Player();
     gui.go();
  }
  public void go() {
     JFrame frame = new JFrame("MP3 Player."); //Creates window.
     CustomPanel base = new CustomPanel(); //Makes the image into a panel.
     JButton button1 = new JButton("Artists");
     JButton button2 = new JButton("Genres");
     JButton button3 = new JButton("Songs");
     JButton button4 = new JButton("TEST");
     JButton button5 = new JButton("TEST");
     button1.setHorizontalAlignment(SwingConstants.LEFT);
     button2.setHorizontalAlignment(SwingConstants.LEFT);
     button3.setHorizontalAlignment(SwingConstants.LEFT);
     button4.setHorizontalAlignment(SwingConstants.LEFT);
     button5.setHorizontalAlignment(SwingConstants.LEFT);
     button1.addActionListener(new Button1Listener());
     button2.addActionListener(new Button2Listener());
     button3.addActionListener(new Button3Listener());
     button4.addActionListener(new Button4Listener());
     button5.addActionListener(new Button5Listener());
     base.add(button1);
     base.add(button2);
       base.add(button3);
         base.add(button4);
         base.add(button5);
         frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
         frame.setSize(304, 360);
         frame.setResizable(false);
         frame.add(base);
         frame.setVisible(true);
         button1.setSize(280, 30);
         button1.setLocation(10,10);
         button1.setBackground(Color.BLACK); 
         button1.setForeground(Color.white);
         button2.setSize(280, 30);
         button2.setLocation(10,40);
         button2.setBackground(Color.BLACK); 
         button2.setForeground(Color.white);
         button3.setSize(280, 30);
         button3.setLocation(10,70);
         button3.setBackground(Color.BLACK); 
         button3.setForeground(Color.white);
         button4.setSize(280, 30);
         button4.setLocation(10,100);
         button4.setBackground(Color.BLACK); 
         button4.setForeground(Color.white);
         button5.setSize(280, 30);
         button5.setLocation(10,130);
         button5.setBackground(Color.BLACK); 
         button5.setForeground(Color.white);
      }
   //These are the actions for the 5 buttons.
    //Need to get buttons straight once first button is clicked
      class Button1Listener implements ActionListener {
         public void actionPerformed(ActionEvent event) {
            if (event.getSource() instanceof JButton) { 
               JButton clickedButton = (JButton) event.getSource(); 
               clickedButton.setSize(280, 30);
               clickedButton.setLocation(10,10);
               clickedButton.setBackground(Color.BLACK); 
               clickedButton.setForeground(Color.white);
               String buttonText = clickedButton.getText(); 
               if (buttonText.equals("Artists")) { 
                  System.out.println("Artists");
                  clickedButton.setText("Back");
               } 
               else if (buttonText.equals("Back")) { 
                  System.out.println("Back");
               } 
            } 
         } 
      }
   //these are just place holders for the other buttons.
      class Button2Listener implements ActionListener {
         public void actionPerformed(ActionEvent event) {
            System.out.println("Genres");
         }
      }
      class Button3Listener implements ActionListener {
         public void actionPerformed(ActionEvent event) {
            System.out.println("Songs");
         }
      }
      class Button4Listener implements ActionListener {
         public void actionPerformed(ActionEvent event) {
            System.out.println("TEST");
         }
      }
      class Button5Listener implements ActionListener {
         public void actionPerformed(ActionEvent event) {
            System.out.println("TEST");
         }
      }
}