/*  资源类 */
class ShareValue {private int total;//判断对象是否为空private boolean isEmpty=true;//判断对象是否已满private boolean isFull=true;public ShareValue(int total) {this.total = total;if(total>0) isEmpty=false;if(total<1000) isFull=false;}/** synchronized 方法控制对类成员变量的访问：每个类实例对应一把锁，每个 synchronized 方法都必须获得调用该方法的类实例的锁方能执行，* 否则所属线程阻塞，方法一旦执行，就独占该锁，直到从该方法返回时才将锁释放，此后被阻塞的线程方能获得该锁，重新进入可执行状态。* 这种机制确保了同一时刻对于每一个类实例，其所有声明为 synchronized 的成员函数中至多只有一个处于可执行状态* （因为至多只有一个能够获得该类实例对应的锁），从而有效避免了类成员变量的访问冲突（只要所有可能访问类成员变量的方法均被声明为 synchronized）。* */synchronized void putValue(int value){//取得当前线程名String name=Thread.currentThread().getName();while(isFull){display("Full ! ["+name+"] waites.");try {this.wait();} catch (InterruptedException e) {System.out.println(e);}}total+=value;if(total>1000){isFull=true;}display(name+",put: "+value+",old value: "+(total-value)+",now value"+total);isEmpty=false;//通知所有的等待线程notifyAll();}synchronized int getValue(int value){String  name=Thread.currentThread().getName();while(isEmpty || total<value){display("Empty or not enough! ["+name+"] waits.");			try {//进入等待状态this.wait();} catch (InterruptedException e) {System.out.println(e);}}display(name+" get: "+value+",old value:"+total+",now value :"+(total-value));if(total-value>=0){total-=value;}if(total==0){isEmpty=true;}if(total<1000){isFull=false;}//通知所有等待的线程notifyAll();return value;}int getNowTotal(){return total;}private void display(String string) {System.out.println(string);}
}/*  生产者类  */
class Producer extends Thread {// 共享的ShareValue对象ShareValue share;// 要增加的值int value;public Producer(String name, ShareValue share, int value) {super(name);this.share = share;this.value = value;}public void run() {//同步share对象 ，直到当前代码块运行完毕后，share的对象锁才会释放synchronized (share) {try {sleep(100);} catch (InterruptedException e) {System.out.println(e);}share.putValue(value);}}
}/*消费者类*/
class Consumer extends Thread{//共享的ShareValue对象ShareValue share;//要减少的值int value;public Consumer(String name,ShareValue share, int value) {super(name);this.share = share;this.value = value;}public void run(){	//同步share对象，直到当前代码运行完毕后，share的对象锁才会释放synchronized (share) {try {sleep(100);} catch (InterruptedException e) {System.out.println(e);}share.getValue(value);}}
} /*  测试主类  */
public class TestDemo {public static void main(String[] args) {ShareValue share=new ShareValue(0);Producer producer1=new Producer("producer1", share, 100);Consumer consumer=new Consumer("consumer", share, 300);Producer producer2=new Producer("producer2",share,950);Producer producer3=new Producer("producer3",share,50);
//		Producer producer4=new Producer("producer4",share,50);
//		Producer producer5=new Producer("producer5",share,50);producer1.start();consumer.start();producer2.start();producer3.start();
//		producer4.start();
//		producer5.start();}}