=========================使用synchronized,配合Object的wait()/notify()实现生产者消费者======================
思考问题：
1.为什么用wait()+notify()实现生产者消费者模式？
wait()方法可以暂停线程，并释放对象锁
notify()方法可以唤醒需要该对象锁的其他线程，并在执行完后续步骤，到了synchronized临界区后，才会把锁释放
2.为什么wait()、notify()、notifyAll()方法需要放在同步代码块中执行？
wait()方法暂停线程执行，并立即释放对象锁 notify()/notifyAll() 方法唤醒其他等待该对象锁的线程,并在执行完同步代码块中的后续步骤后，释放对象锁 notify()和notifyAll()的区别在于：
notify只会唤醒其中一个线程，
notifyAll则会唤醒全部线程。 至于notify会唤醒哪个线程，是由线程调度器决定的。
因为这三个方法都需要获取到对象锁才能有效执行。否则就会抛异常：java.lang.IllegalMonitorStateException
3.wait()是暂停的哪个线程？notify()唤醒的是哪个线程？
wait()是暂停当前线程。 notify()则是唤醒等待当前对象锁的线程
4.什么是生产者消费者模式
一个产数据，一个用数据，中间最多再加上个存取仓库
生产者消费者模式 就是java多线程通信一个很好的例子
5.生产着消费者模式特点是什么
1.解耦，生产者干生产者的事情，消费者干消费者的事情 2.支持高并发，可以同时多个生成，多个消费，互不影响
6.一对一的生产者消费者模式：
1>早餐类：
package com.sxd.swapping.test.ProducerAndConsumerTest; /**
* 早餐基础类
*
* wait()
* notify()
* notifyAll()
* 三个方法 需要放在同步代码块中执行 因为要获取对象锁
*/
public class Breakfast{
private String food; private String drink; private boolean flag = false;//flag = false 表示需要生产 flag = true 表示需要消费 public synchronized void makeBreakfast(String food,String drink){ System.out.println("生产者进入--->标志值为："+flag);
if (flag){
try {
System.out.println("make---wait()暂停，释放对象锁");
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
} this.food = food;
try {
System.out.println("make---sleep()休眠,不释放对象锁");
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
} this.drink = drink;
System.out.println("make---生产者制造东西完成----");
this.flag = true;
System.out.println("make---notify()唤醒，标志值为"+flag);
notify();
} public synchronized void eatBreakfast(){ System.out.println("消费者进入--->标志值为："+flag);
if(!flag){
try {
System.out.println("eat---wait()");
wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
} try {
System.out.println("eat---sleep()");
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("吃东西---"+this.food+";喝东西---"+this.drink);
this.flag = false;
System.out.println("eat---notify()唤醒，标志值为"+flag);
notify();
}
}
2> 生产者类：
package com.sxd.swapping.test.ProducerAndConsumerTest;
public class Producer implements Runnable{
private Breakfast breakfast;
public Producer(Breakfast breakfast) {
this.breakfast = breakfast;
}
@Override
public void run() {
int i = 7;
for (int i1 = 0; i1 < i; i1++) {
if (i1 %2 == 0){
this.breakfast.makeBreakfast("馒头","豆浆");
}else {
this.breakfast.makeBreakfast("面包","冷饮");
}
}
}
}
3>消费者类：
package com.sxd.swapping.test.ProducerAndConsumerTest;
public class Consumer implements Runnable{
private Breakfast breakfast;
public Consumer(Breakfast breakfast) {
this.breakfast = breakfast;
}
@Override
public void run() {
int i = 7;
for (int i1 = 0; i1 < i; i1++) {
System.out.println("星期"+(i1+1)+"---消费者要来吃东西了");
this.breakfast.eatBreakfast();
}
}
}
4>线程启动主测试类：
package com.sxd.swapping.test.ProducerAndConsumerTest;
public class Test {
public static void main(String[] args) {
Breakfast breakfast = new Breakfast();
new Thread(new Producer(breakfast)).start();
new Thread(new Consumer(breakfast)).start();
}
}
5>展示结果：
===========================使用Lock,配合Condition的await()/signal()实现生产者消费者============================
1.早饭类，提供生产方法和消费方法
package com.sxd.swapping.test.ProducerAndConsumerTest; import java.util.LinkedList;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock; /**
*
* Lock配合condition实现生产者消费者模式
*
* @author sxd
* @date 2019/8/6 9:08
*/
public class Condition_Breakfast { private LinkedList<String> breakfastList;//早饭资源容器 private int maxSize;//最大量早饭资源数量 自定义 private Lock lock; //锁 private Condition comsumerCondition;//满条件【即代表消费者等待队列】 private Condition producerCondition;//不满条件【即代表生产者等待队列】 //自定义 最大共享资源数量
public Condition_Breakfast(int maxSize) {
this.maxSize = maxSize;
breakfastList = new LinkedList<>();
lock = new ReentrantLock();
comsumerCondition = lock.newCondition();
producerCondition = lock.newCondition();
} public void produce(String str){
lock.lock();
try {
while (maxSize == breakfastList.size()){
System.out.println("如果早餐共享资源已经满足最大量，则进入本方法的当前线程们，进入notFullCondition的等待队列中，线程挂起");
producerCondition.await();
} breakfastList.add(str);
System.out.println("生产早饭："+str); System.out.println("早饭已经被生产了，唤醒消费者等待队列中的线程，可以继续开始消费了");
comsumerCondition.signal();
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
lock.unlock();
}
} public String consume(){
String str = null;
lock.lock(); try {
while (breakfastList.size() == 0 ){
System.out.println("如果早饭共享资源完全==0，就将消费者们挂起，等待生产者生产后再去唤醒消费者们");
comsumerCondition.await();
} str = breakfastList.poll();
System.out.println("消费早饭："+str); System.out.println("早饭已经被消费了，唤醒生产者等待队列中的 线程，可以继续生产了");
producerCondition.signal();
} catch (InterruptedException e) {
e.printStackTrace();
}finally {
lock.unlock();
} return str;
} }
2.早饭类的生产者
package com.sxd.swapping.test.ProducerAndConsumerTest; /**
* @author sxd
* @date 2019/8/6 9:26
*/
public class Condition_Producer implements Runnable { Condition_Breakfast breakfast; public Condition_Producer(Condition_Breakfast breakfast) {
this.breakfast = breakfast;
} @Override
public void run() {
int i = 7;
String threadName = Thread.currentThread().getName();
for (int i1 = 0; i1 < i; i1++) {
if (i1 %2 == 0){
this.breakfast.produce(threadName+"大馒头"+i1);
}else {
this.breakfast.produce(threadName+"大包子"+i1);
}
}
}
}
3.早饭类的消费者
package com.sxd.swapping.test.ProducerAndConsumerTest; /**
* @author sxd
* @date 2019/8/6 9:28
*/
public class Condition_Comsumer implements Runnable{ Condition_Breakfast breakfast; public Condition_Comsumer(Condition_Breakfast breakfast) {
this.breakfast = breakfast;
} @Override
public void run() {
int i = 7;
for (int i1 = 0; i1 < i; i1++) {
this.breakfast.consume();
}
}
}
4.测试类
package com.sxd.swapping.test.ProducerAndConsumerTest; /**
* @author sxd
* @date 2019/8/6 9:30
*/
public class Test2 { public static void main(String[] args) {
Condition_Breakfast breakfast = new Condition_Breakfast(16);
new Thread(new Condition_Producer(breakfast)).start();
new Thread(new Condition_Producer(breakfast)).start();
new Thread(new Condition_Producer(breakfast)).start();
new Thread(new Condition_Comsumer(breakfast)).start();
new Thread(new Condition_Comsumer(breakfast)).start();
new Thread(new Condition_Comsumer(breakfast)).start(); } }