紧急求助，cannot resolve symbol

[kkkgho]

我编写了一个程序，不知道为什么会出现5个错误？？

D:\>javac Mingqu.java
Mingqu.java:37: cannot resolve symbol
symbol : class Actionevent
location: class Mingqu
public void actionPerformed(Actionevent e){
^
Mingqu.java:21: menu is already defined in init()
JMenu menu=new JMenu("音乐");
^
Mingqu.java:29: cannot resolve symbol
symbol : variable menuItem4d
location: class Mingqu
menu.add(menuItem4d);
^
Mingqu.java:30: cannot resolve symbol
symbol : variable menuBar
location: class Mingqu
menuBar.add(menu);
^
Mingqu.java:35: cannot resolve symbol
symbol : variable menuBar
location: class Mingqu
return menuBar;
^
5 errors


大家帮我看看到底是那里搞错了？？？！
谢谢了！！
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.applet.*;
import java.net.*;

public class Mingqu implements ActionListener{
JMenuItem menuItem1,menuItem2,menuItem3,menuItem4;
AudioClip sound=loadSound("1.wav");
static JFrame frame;
public static void main(String args[]){
frame=new JFrame("名曲欣赏");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Mingqu ming=new Mingqu();
frame.setJMenuBar(ming.init());
frame.setSize(250,150);
frame.setVisible(true);
}
public JMenuBar init(){
JMenuBar menu=new JMenuBar();
JMenu menu=new JMenu("音乐");
menuItem1=new JMenuItem("播放");
menu.add(menuItem1);
menuItem2=new JMenuItem("循环");
menu.add(menuItem2);
menuItem3=new JMenuItem("停止");
menu.add(menuItem3);
menuItem4=new JMenuItem("退出");
menu.add(menuItem4d);
menuBar.add(menu);
menuItem1.addActionListener(this);
menuItem2.addActionListener(this);
menuItem3.addActionListener(this);
menuItem4.addActionListener(this);
return menuBar;
}
public void actionPerformed(Actionevent e){
if(e.getSource==menuItem1) sound.play();
if(e.getSource==menuItem2) sound.loop();
if(e.getSource==menuItem3) sound.stop();
if(e.getSource==menuItem4) System.exit(0);
}
private AudioClip loadSound(String fileName){
URL url=null;
try{ url=new URL("file:"+System.getProperty("user.dir")+"/"+fileName);}
catch(MalformedURLException e){}
return Applet.newAudioClip(url);
}
}

[kkkgho]

是一个音乐播放器

[anqini]

错误太多了，大小写问题，变量同名问题！方法名字问题，我给你改了，自己看看

package zhao;

import java.applet.Applet;
import java.applet.AudioClip;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.net.MalformedURLException;
import java.net.URL;

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

public class Mingqu implements ActionListener {

    JMenuItem menuItem1, menuItem2, menuItem3, menuItem4;

    AudioClip sound = loadSound("1.wav");

    static JFrame frame;

    public static void main(String args[]) {
        frame = new JFrame("dads");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Mingqu ming = new Mingqu ();
        frame.setJMenuBar(ming.init());
        frame.setSize(
            250,
            150);
        frame.setVisible(true);
    }

    public JMenuBar init() {
        JMenuBar menuBar = new JMenuBar();//这里你跟下行的menu变量名重复了
        JMenu menu = new JMenu("音乐");
        menuItem1 = new JMenuItem("播放");
        menu.add(menuItem1);
        menuItem2 = new JMenuItem("循环");
        menu.add(menuItem2);
        menuItem3 = new JMenuItem("停止");
        menu.add(menuItem3);
        menuItem4 = new JMenuItem("退出");
         menu.add(menuItem4);//menuItem4d哪里来的？改为menuItem4
        menuBar.add(menu);
        menuItem1.addActionListener(this);
        menuItem2.addActionListener(this);
        menuItem3.addActionListener(this);
        menuItem4.addActionListener(this);
        return menuBar;
    }

    public void actionPerformed(ActionEvent e) {//ActionEvent 之前你写成Actionevent 
        if (e.getSource() == menuItem1)//getSource这个之前你写错了
            sound.play();
        if (e.getSource() == menuItem2)
            sound.loop();
        if (e.getSource() == menuItem3)
            sound.stop();
        if (e.getSource() == menuItem4)
            System.exit(0);
    }

    private AudioClip loadSound(String fileName) {
        URL url = null;
        try {
            url = new URL("file:" + System.getProperty("user.dir") + "/" + fileName);
        } catch (MalformedURLException e) {
        }
        return Applet.newAudioClip(url);
    }

}

[Shine_Panda]

楼上正是好心人啊。。。。。。。。
学习。。。。

[tianyidan]

学习！不在行这个。帮顶了。

[eswn]

1.ActionEvent写错了
2. JMenuBar menu = new JMenuBar();
JMenu menu = new JMenu("音乐");
menu定义重复了.