JAVA 버튼 눌러서 이미지 바꾸기

mport java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.event.*; class A extends JFrame implements ActionListener{ Container con; private ImageIcon before = new ImageIcon("a.jpg"); private ImageIcon after = new ImageIcon("b.jpg"); private JButton b1 = new JButton(before); private JButton b2 = new JButton(after);; A(){ init(); start(); setSize(500,500); setVisible(true); } void init(){ b1.setIconTextGap(1); b2.setIconTextGap(1); con=this.getContentPane(); con.add("Center",b1); } void start(){ b1.addActionListener(this); b2.addActionListener(this); } public void actionPerformed(ActionEvent e){ if((e.getSource()).equals(b1)){ con.removeAll(); con.add(b2); b2.updateUI(); } else{ con.removeAll(); con.add(b1); b1.updateUI(); } } public static void main(String[] args) { new A(); } }
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