多线程模式-Worker Thread[转]

1 示例

• ClientTjread.java

package com.gc.language;

public class ClientThread extends Thread{
    private Channel channel; 
    public ClientThread(Channel channel) {
            this.channel = channel;
        }
     
    public void run (){
        
        for(int i =0;i<15;i++)
        {
            try{
                Thread.sleep(50);
                }
                catch(InterruptedException e){
                    
                }
            channel.putRequest(new Request());
                
            
        }
        
    }

}

• Request.java

package com.gc.language;

import java.util.Date;

public class Request { 
    // .... 
    
    public void execute() { 
        // do some work.... 
        
        System.out .println(new Date());
        
    } 
} 

• WorkerThread.java

package com.gc.language;

public class WorkerThread extends Thread { 
    private Channel channel;

    public WorkerThread(Channel channel) {
        this.channel = channel;
    }

    // ... 

    public void run() { 
        while(true) { 
            try{
            Thread.sleep(5000);
            }
            catch(InterruptedException e){
                
            }
            Request request = channel.getRequest(); 
            request.execute();
           
        } 
    } 
} 

• Channel.java

package com.gc.language;

import java.util.LinkedList; 

public class Channel { 
    private LinkedList requests; 
    private WorkerThread[] workerThreads; 

    public Channel(int threadNumber) { 
        requests = new LinkedList(); 
        ClientThread cthread = new ClientThread (this);
        cthread.start();
        workerThreads = new WorkerThread[threadNumber]; 
        for(int i = 0; i < workerThreads.length; i++) { 
            workerThreads[i] = new WorkerThread(this); 
            workerThreads[i].start(); 
        } 
    } 

    public synchronized void putRequest(Request request) { 
        while(requests.size() >= 2) { // 容量限制為 2 
            try { 
                wait(); 
            } 
            catch(InterruptedException e) {} 
        } 

        requests.addLast(request); 
        notifyAll(); 
    } 
    
    public synchronized Request getRequest() { 
        while(requests.size() <= 0) { 
            try { 
                wait(); 
            } 
            catch(InterruptedException e) {} 
        } 

        Request request = (Request) requests.removeFirst(); 
        notifyAll(); 
      
        return request;
    } 
} 

• Test.java

package com.gc.language;


public class Test {
    public static void main(String[] args){
        
        Channel channel = new Channel(10);
    }


}
2 观念
Worker Thread模式在Request的管理上像P-C模式，在Request的行为上像Command模式。P-C模式关注Product(Request)如何生产消费，Worker Thread模式关注产品被消费时做何处理。