并发编程-wait,notify实现队列功能

import java.util.LinkedList;

import java.util.concurrent.TimeUnit;

import java.util.concurrent.atomic.AtomicInteger;

public class MyQueue {

//1 需要一个承装元素的集合 
private LinkedList<Object> list = new LinkedList<Object>();

//2 需要一个计数器
private AtomicInteger count = new AtomicInteger(0);

//3 需要制定上限和下限
private final int minSize = 0;

private final int maxSize ;

//4 构造方法
public MyQueue(int size){
this.maxSize = size;
}

//5 初始化一个对象 用于加锁
private final Object lock = new Object();

//put(anObject): 把anObject加到BlockingQueue里,如果BlockQueue没有空间,则调用此方法的线程被阻断，直到BlockingQueue里面有空间再继续.
public void put(Object obj){
synchronized (lock) {
while(count.get() == this.maxSize){
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//1 加入元素
list.add(obj);
//2 计数器累加
count.incrementAndGet();
//3 通知另外一个线程（唤醒）
lock.notify();
System.out.println("新加入的元素为:" + obj);
}
}

//take: 取走BlockingQueue里排在首位的对象,若BlockingQueue为空,阻断进入等待状态直到BlockingQueue有新的数据被加入.
public Object take(){
Object ret = null;
synchronized (lock) {
while(count.get() == this.minSize){
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
//1 做移除元素操作
ret = list.removeFirst();
//2 计数器递减
count.decrementAndGet();
//3 唤醒另外一个线程
lock.notify();
}
return ret;
}

public int getSize(){
return this.count.get();
}

public static void main(String[] args) {

final MyQueue mq = new MyQueue(5);
mq.put("a");
mq.put("b");
mq.put("c");
mq.put("d");
mq.put("e");

System.out.println("当前容器的长度:" + mq.getSize());

Thread t1 = new Thread(new Runnable() {
@Override
public void run() {
mq.put("f");
mq.put("g");
}
},"t1");

t1.start();

Thread t2 = new Thread(new Runnable() {
@Override
public void run() {
Object o1 = mq.take();
System.out.println("移除的元素为:" + o1);
Object o2 = mq.take();
System.out.println("移除的元素为:" + o2);
}
},"t2");

try {
TimeUnit.SECONDS.sleep(2);
} catch (InterruptedException e) {
e.printStackTrace();
}

t2.start();

}

}