Java 实现读者与写者

package r_d;
/**
 * 以下读者与写者实验以swing为主要实现
 */
import java.awt.*;
import javax.swing.*;
import javax.swing.border.TitledBorder;

import java.awt.event.*;
import java.util.Random;
import java.util.concurrent.Semaphore;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
public class Rw2 extends JFrame implements ActionListener{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    
    final Semaphore mutex=new Semaphore(1);
    final Semaphore Rmutex=new Semaphore(5);
    private boolean r=false;
    private int counter=0;
    ExecutorService exc=Executors.newCachedThreadPool();
    private Random ran=new Random();
    //界面设计控件
    Container con=getContentPane();
        JLabel bName,blank;
        JLabel []read=new JLabel[5];
        JLabel []w=new JLabel[2];
        JTextArea tf_bContent;
        JTextArea []tf_r=new JTextArea[5];
        JTextArea []tf_w=new JTextArea[2];
        Button b_r,b_w;

    public Rw2(){
        con.setLayout(null);
        setTitle("读者和写者问题");
        bName=new JLabel("三国演义");
        bName.setBounds(30, 30, 60, 40);
        tf_bContent=new JTextArea("《三国演义》中国古典四大名著之一");
        tf_bContent.setBounds(30, 60, 300, 80);
        tf_bContent.setBorder(new TitledBorder(null,"",TitledBorder.DEFAULT_JUSTIFICATION,
                TitledBorder.DEFAULT_POSITION,null,Color.blue));
        blank=new JLabel();
        //读者控件初始化
        for(int i=0;i<5;i++)
        {
            
            read[i]=new JLabel();
            read[i].setText("读者"+String.valueOf(i));
            read[i].setBounds(10, 150+60*i, 60, 50);
            
            tf_r[i]=new JTextArea();
            tf_r[i].setBounds(60, 150+60*i, 100, 50);
            tf_r[i].setBorder(new TitledBorder(null, "", TitledBorder.DEFAULT_JUSTIFICATION, 
                    TitledBorder.DEFAULT_POSITION, null, Color.BLUE));
        
        }
        for(int j=0;j<2;j++)
        {
            w[j]=new JLabel();
            w[j].setText("写者"+String.valueOf(j));
            w[j].setBounds(200, 150+60*j, 100, 50);
            tf_w[j]=new JTextArea();
            tf_w[j].setBounds(260, 150+60*j, 100, 50);
            tf_w[j].setBorder(new TitledBorder(null, "", TitledBorder.DEFAULT_JUSTIFICATION, 
                    TitledBorder.DEFAULT_POSITION, null, Color.BLUE));
        }
        
        b_r=new Button("启动读者线程");
        b_w=new Button("启动写者线程");
        b_r.setBounds(400,100, 100, 50);
        b_w.setBounds(510,100, 100, 50);
        //安装行动监视器
        b_r.addActionListener(this);
        b_w.addActionListener(this);
        
      
        con.add(bName);
        con.add(tf_bContent);
        for(int i=0;i<5;i++)
        {
            con.add(tf_r[i]);
            con.add(read[i]);
        }
        for(int j=0;j<2;j++)
        {
            
            con.add(w[j]);
            con.add(tf_w[j]);
        }
        con.add(b_r);
        con.add(b_w);
        setSize(800,500);
        setVisible(true);
        //关闭窗口
        addWindowListener(new WindowAdapter(){
        public void windowClosing(WindowEvent e){
            System.exit(0);
        }    
        });
                
    }
    
    
    Runnable run=new Runnable(){
        public void run(){
            if(r)
            {
                try {
                    Rmutex.acquire();
                    if(counter==0)
                    {
                        try {
                            mutex.acquire();                       
                        } catch (InterruptedException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                    }
                    tf_r[counter].setText(tf_bContent.getText().toString()); 
                    counter++;
                    Thread.sleep((long)(Math.random()*10000));
                    tf_r[counter-1].setText("");
                    if(counter==1)
                           mutex.release();
                    counter--;
                    Rmutex.release();
                
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    //e.printStackTrace();
                }
                
                
    
            }else if(!r)
            {
                try {
                    mutex.acquire();
                    tf_bContent.setText(tf_w[ran.nextInt(1)].getText().toString());
                    Thread.sleep((long)(Math.random()*10000));
                    mutex.release();
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                
            }
        }
        
    };//run
    @Override
    public void actionPerformed(ActionEvent a) {
        // TODO Auto-generated method stub
        if(a.getSource()==b_r)
        {
            r=true;
            exc.execute(run);
            
        }
        else if(a.getSource()==b_w){
            r=false;
            exc.execute(run);
        }
        
    }
    public static void main(String args[])
    {
        new Rw2();
    }
}