练习:生产者 消费者。
这里面最主要的知识点是:另外一种线程间的通信,另外一种锁的表达。
import java.util.concurrent.locks.*;
class ProducerConsumerDemo2
{
public static void main(String[] args)
{
Resource r = new Resource();
Producer pro = new Producer(r);
Consumer con = new Consumer(r);
Thread t1 = new Thread(pro);
Thread t2 = new Thread(pro);
Thread t3 = new Thread(con);
Thread t4 = new Thread(con);
t1.start();
t2.start();
t3.start();
t4.start();
}
}
class Resource
{
private String name;
private int count = 1;
private boolean flag = false;
private Lock lock = new ReentrantLock();
private Condition condition_pro = lock.newCondition();
private Condition condition_con = lock.newCondition();
public void set(String name)throws InterruptedException
{
lock.lock();//将同步替换成了lock操作。
try
{
while(flag) //定义while判断标记是因为要让被唤醒的线程再一次判断标记。
condition_pro.await();
this.name = name+"--"+count++;
System.out.println(Thread.currentThread().getName()+"....生产者...."+this.name);
flag = true;
condition_con.signal();//实现了本方只唤醒对方的操作。
}
finally
{
lock.unlock();//释放锁的动作一定要执行。
}
}
public void out()throws InterruptedException
{
lock.lock();
try
{
while(!flag)
condition_con.await();
System.out.println(Thread.currentThread().getName()+"....消费者..........."+this.name);
flag = false;
condition_pro.signal();
}
finally
{
lock.unlock();
}
}
}
class Producer implements Runnable
{
private Resource res;
Producer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
try
{
res.set("+商品+");
}
catch(InterruptedException e)
{
}
}
}
}
class Consumer implements Runnable
{
private Resource res;
Consumer(Resource res)
{
this.res = res;
}
public void run()
{
while(true)
{
try
{
res.out();
}
catch(InterruptedException e)
{
}
}
}
}
|