黑马程序员_多线程：生产者消费者练习实例及问题

今天把这个题目练习了一下，但是出现了一些问题，就是如何有效控制产品的产生数量，希望有人给讲解一下！

package com.itpractice;

import java.util.concurrent.locks.Condition;

import java.util.concurrent.locks.Lock;

import java.util.concurrent.locks.ReentrantLock;

public class ProducerAndConsumerDemo2 {

public static void main(String[] args) {

Resource2 res = new Resource2();

Thread t1 = new Thread(new Producer2(res));
Thread t2 = new Thread(new Producer2(res));
Thread t3 = new Thread(new Consumer2(res));
Thread t4 = new Thread(new Consumer2(res));

t1.start();
t2.start();
t3.start();
t4.start();
}

}

class Resource2 {
private String name;
private int count = 1;
private boolean flag = false;

private Lock lock = new ReentrantLock();

private Condition con_pro = lock.newCondition();
private Condition con_con = lock.newCondition();

public void setResource(String name) throws InterruptedException {

lock.lock();
try {
while (flag)
con_pro.await();
this.name = name + count++;

System.out.println(Thread.currentThread().getName() + "---生产者---"
+ this.name);
flag = true;
con_con.signal();
} finally {
lock.unlock();
}
}

public void outResource() throws InterruptedException {
lock.lock();
try {
while (!flag)
con_con.await();
System.out.println(Thread.currentThread().getName() + "---消费者---"
+ this.name);
flag = false;
con_pro.signal();
} finally {
lock.unlock();
}
}

}

class Producer2 implements Runnable {

private Resource2 res;

private int x = 0;

Producer2(Resource2 res) {
this.res = res;
}

public void run() {
while (x < 10) {
try {
res.setResource("产品");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

}

class Consumer2 implements Runnable {

private Resource2 res;

Consumer2(Resource2 res) {
this.res = res;
}

public void run() {
while (true) {
try {
res.outResource();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

}