问题：Multiple markers at this line - ButtonHandler cannot be resolved to a type

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class EventHandlingUse1 extends JFrame{
public EventHandlingUse1(){
super("使用匿名类的时间处理应用");
Container c=getContentPane();
JButton b=new JButton("单击0次");
b.addActionListener(new ActionListener(){
int count=0;
public void actionPerformed(ActionEvent e){
JButton b=(JButton)e.getSource();
b.setText("单击"+(++count)+"次");
}
}
);
ButtonHandler bh=new ButtonHandler();//出错处
b.addActionListener(bh);
class ButtonHandler implements ActionListener{
int count=0;
public void actionPerformed(ActionEvent e){
JButton b=(JButton)e.getSource();
b.setText("单击"+(++count)+"次");
}
}
c.add(b,BorderLayout.CENTER);
}
public static void main(String args[]){
EventHandlingUse1 app=new EventHandlingUse1();
app.setSize(160,120);
app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
app.setVisible(true);
}

}

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