java abstract method_java错误：TitleChanger is not abstract and does not override abstract method 这个怎么修...

这是错误提示：TitleChangerisnotabstractanddoesnotoverrideabstractmethodactionPerformed(java.awt.event.ActionEvent)injava.awt.event.ActionListener这是我的代码：importjava....

这是错误提示：TitleChanger is not abstract and does not override abstract method actionPerformed(java.awt.event.ActionEvent)in java.awt.event.ActionListener

这是我的代码：

import java.awt.event.*;

import javax.swing.*;

import java.awt.*;

public class TitleChanger extends JFrame implements ActionListener{

JButton b1;

JButton b2;

public TitleChanger(){

super("Title Bar");

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setLookAndFeel();

b1 = new JButton("Rosencrantz");

b2 = new JButton("Guildenstern");

b1.addActionListener(this);

b2.addActionListener(this);

FlowLayout flow = new FlowLayout();

setLayout(flow);

add(b1);

add(b2);

pack();

setVisible(true);

}

public void actionPerformd(ActionEvent evt){

Object source = evt.getSource();

if(source == b1){

setTitle("Rosencrantz");

}else if(source == b2){

setTitle("Guildenstern");

}

repaint();

}

private void setLookAndFeel(){

try{

UIManager.setLookAndFeel(

"com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel"

);

SwingUtilities.updateComponentTreeUI(this);

}catch(Exception e){

System.err.println("Couldn`t use the system "

+ "look and feel: "+e);

}

}

public static void main(String[] arguments){

TitleChanger frame = new TitleChanger();

}

}

展开