Java-J2SE学习笔记-线程-生产者消费者问题

一、概述

模拟生产者消费者问题

二、代码

1.Consumer.java

2.Producer.java

3.SyncStack.java

4.Test.java

1.Consumer.java

package ProducerConsumer;

public class Consumer implements Runnable {

private SyncStack syncStack;

public Consumer(SyncStack syncStack) {
super();
this.syncStack = syncStack;
}

public  void consume(){
Product p;
for(int i = 0 ; i < 10 ; i++){
p = syncStack.pop();
System.out.println("******消费了:"+p);
}
}

@Override
public void run() {
//		try {
//			Thread.sleep(10);
//		} catch (InterruptedException e) {
//			e.printStackTrace();
//		}
consume();
}
}

　　

2.Producer.java

package ProducerConsumer;

public class Producer implements Runnable {

private SyncStack syncStack;

public Producer(SyncStack syncStack) {
super();
this.syncStack = syncStack;
}

public  void produce(){
for(int i = 0 ; i < 10 ; i++){
Product p = new Product(i);
syncStack.push(p);
System.out.println("生产了:"+p);
}
}

@Override
public void run() {
produce();
}
}

　　

3.SyncStack.java

package ProducerConsumer;

import java.util.ArrayList;
import java.util.List;

public class SyncStack {

int index = 0;
Product [] ps = new Product[6];
//List<Product> ps = new ArrayList<Product>();

public synchronized void  push(Product p) {
//if(index == ps.length){ //不能用if判断，若用if，则this.wait()出现异常时，代码仍会往下执行
while(index == ps.length){
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notifyAll();
ps[index] = p;
index = index + 1;
//System.out.println(index);
}

public synchronized Product  pop() {
while(index == 0){
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notifyAll();
index --;
return ps[index];
//		System.out.println("ps===="+ps);
//		Product p = ps.get(ps.size()-1);
//		ps.remove(ps.size()-1);
//		return p;

}
}

　　

4.Test.java

package ProducerConsumer;

public class Test {

public static void main(String[] args) {
SyncStack ss = new SyncStack();

Producer p1 = new Producer(ss);
Consumer c1 = new Consumer(ss);

Thread tp1 = new Thread(p1);
Thread tc1 = new Thread(c1);

tc1.start();
tp1.start();
new Thread(new Producer(ss)).start();
new Thread(new Consumer(ss)).start();
}
}

　　

三、运行结果



四、小结

1.this.wait(),保有先锁定，才能调用wait,wait是使正在访问本对象的线程wait,且wait后此线程的锁会丢失，只有当线程醒来后才会再去找回锁。sleep则锁不会丢失。

2.this.notify()唤醒一个正在wait当前对象上的一个线程