Java 多线程 （PART XVI）生产者消费者（I） 单个生产者单个消费者

图解：

代码：

package produceandconsume;

class ValueObject {
//缓冲区
public static String value = "";
}

class P {
private Object lock;

public P(Object lock) {
this.lock = lock;
}

public void setValue() {
try {
synchronized (lock) {
if (!ValueObject.value.equals("")) {
//检查缓冲区如果消费者还没有将物品取走则等待
lock.wait();
}
//向缓冲区放入物品，并且通知消费者
String value = System.currentTimeMillis() + "_" + System.nanoTime();
System.out.println("set 的值是" + value);
ValueObject.value = value;
lock.notify();
}

} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

class C {
private Object lock;

public C(Object lock) {
this.lock = lock;
}

public void getValue() {
try {
synchronized (lock) {
if (ValueObject.value.equals("")) {
//检查缓冲区如果生产者还没有生产则等待
lock.wait();
}
//取得缓冲区里的值，并且通知生产者
System.out.println("get 的值是" + ValueObject.value);
ValueObject.value = "";
lock.notify();
}

} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
//生产者线程
class ThreadP extends Thread {
private P p;

public ThreadP(P p) {
this.p = p;
}

@Override
public void run() {
while (true) {
p.setValue();
}
}
}
//消费者线程
class ThreadC extends Thread {
private C c;

public ThreadC(C c) {
this.c = c;
}

@Override
public void run() {
while (true) {
c.getValue();
}
}
}

public class Main {

public static void main(String[] args) {
Object lock = new Object();
P p = new P(lock);
C c = new C(lock);
ThreadP pthread = new ThreadP(p);
ThreadC cthread = new ThreadC(c);
//启动生产者消费者线程
pthread.start();
cthread.start();
}

}

运行结果：

set 的值是1507613938571_6935150933094
get 的值是1507613938571_6935150933094
set 的值是1507613938571_6935150954031
get 的值是1507613938571_6935150954031
set 的值是1507613938571_6935150973736
get 的值是1507613938571_6935150973736
set 的值是1507613938571_6935150993851
get 的值是1507613938571_6935150993851
set 的值是1507613938571_6935151013967
get 的值是1507613938571_6935151013967
set 的值是1507613938571_6935151036135
get 的值是1507613938571_6935151036135
set 的值是1507613938571_6935151056661
get 的值是1507613938571_6935151056661
set 的值是1507613938571_6935151076366
get 的值是1507613938571_6935151076366
set 的值是1507613938571_6935151096071
get 的值是1507613938571_6935151096071