用 wait-notify 解决生产者-消费者问题 


//生产者
 1 package com.mzj.test;  
 2 import java.util.Vector;  
 3 import java.util.logging.Level;  
 4 import java.util.logging.Logger;  
 5   
 6 public class Producer implements Runnable {  
 7   
 8     private final Vector sharedQueue;  
 9     private final int SIZE;  
10       
11     public Producer(Vector sharedQueue, int size) {  
12         this.sharedQueue = sharedQueue;  
13         this.SIZE = size;  
14     }  
15       
16    @Override  
17     public void run() {  
18         // TODO Auto-generated method stub  
19         for (int i = 0; i < 7; i++) {  
20             System.out.println("Produced:" + i);  
21             try {  
22                 produce(i);  
23             } catch (InterruptedException ex) {  
24                 Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex);  
25             }  
26         }  
27     }  
28   
29     private void produce(int i) throws InterruptedException {  
30           
31         //wait if queue is full  
32         while (sharedQueue.size() == SIZE) {  
33             synchronized (sharedQueue) {  
34                 System.out.println("Queue is full " + Thread.currentThread().getName()  
35                         + " is waiting , size: " + sharedQueue.size());  
36                 sharedQueue.wait();  
37             }  
38         }  
39           
40         //producing element and notify consumers  
41         synchronized (sharedQueue) {  
42             sharedQueue.add(i);  
43             sharedQueue.notifyAll();  
44         }  
45     }  
46 }

消费者

 1 package com.mzj.test;  
 2 import java.util.Vector;  
 3 import java.util.logging.Level;  
 4 import java.util.logging.Logger;  
 5   
 6 public class Consumer implements Runnable {  
 7   
 8     private final Vector sharedQueue;  
 9     private final int SIZE;  
10       
11     public Consumer(Vector sharedQueue, int size) {  
12         this.sharedQueue = sharedQueue;  
13         this.SIZE = size;  
14     }  
15   
16     @Override  
17     public void run() {  
18         // TODO Auto-generated method stub  
19         while (true) {  
20             try {  
21                 System.out.println("Consumer: " + consume());  
22                 Thread.sleep(50);  
23             } catch (InterruptedException ex) {  
24                 Logger.getLogger(Consumer.class.getName()).log(Level.SEVERE, null, ex);  
25             }  
26         }  
27     }  
28       
29     private int consume() throws InterruptedException {  
30           
31         //wait if queue is empty  
32         while (sharedQueue.isEmpty()) {  
33             synchronized (sharedQueue) {  
34                 System.out.println("Queue is empty " + Thread.currentThread().getName()  
35                         + " is waiting , size: " + sharedQueue.size());  
36                 sharedQueue.wait();  
37             }  
38         }  
39           
40         //otherwise consume element and notify waiting producer  
41         synchronized (sharedQueue) {  
42             sharedQueue.notifyAll();  
43             return (Integer) sharedQueue.remove(0);  
44         }  
45     }  
46 }

测试

 1 package com.mzj.test;  
 2 import java.util.Vector;  
 3   
 4 public class ProducerConsumerSolution {  
 5   
 6     public static void main(String[] args) {  
 7         Vector sharedQueue = new Vector();  
 8         int size = 4;  
 9         Thread prodThread = new Thread(new Producer(sharedQueue, size), "Producer");  
10         Thread consThread = new Thread(new Consumer(sharedQueue, size), "Consumer");  
11         prodThread.start();  
12         consThread.start();  
13     }  
14 }

 

posted @ 2018-10-25 10:09  孟阳miss  阅读(547)  评论(0)  编辑  收藏  举报