/**
* @author yz
* @version 1.0
* @date 2020/10/31 11:24
*/
public class YzBlockingQuery {
private Object[] tab; //队列容器
private int takeIndex; //出队下标
private int putIndex; //入队下标
private int size;//元素数量
private ReentrantLock reentrantLock = new ReentrantLock();
private Condition notEmpty;//读条件
private Condition notFull;//写条件
public YzBlockingQuery(int tabCount) {
if (tabCount <= 0) {
new NullPointerException();
}
tab = new Object[tabCount];
notEmpty = reentrantLock.newCondition();
notFull = reentrantLock.newCondition();
}
public boolean offer(Object obj) {
if (obj == null) { throw new NullPointerException(); }
try {
//获取锁
reentrantLock.lock();
//队列已满
while (size==tab.length){
System.out.println("队列已满");
//堵塞
notFull.await();
}
tab[putIndex]=obj;
if( putIndex==tab.length){
putIndex=0;
}
size ;
//唤醒读线程
notEmpty.signal();
return true;
} catch (Exception e) {
//唤醒读线程
notEmpty.signal();
} finally {
reentrantLock.unlock();
}
return false;
}
public Object take(){
try {
reentrantLock.lock();
while (size==0){
System.out.println("队列空了");
//堵塞
notEmpty.await();
}
Object obj= tab[takeIndex];
//如果到了最后一个，则从头开始
if( takeIndex==tab.length){
takeIndex=0;
}
size--;
//唤醒写线程
notFull.signal();
return obj;
}catch (Exception e){
//唤醒写线程
notFull.signal();
}finally {
reentrantLock.unlock();
}
return null;
}
public static void main(String[] args) {
Random random = new Random(100);
YzBlockingQuery yzBlockingQuery=new YzBlockingQuery(5);
Thread thread1 = new Thread(() -> {
for (int i=0;i<100;i ) {
try {
Thread.sleep(300);
} catch (InterruptedException e) {
e.printStackTrace();
}
yzBlockingQuery.offer(i);
System.out.println("生产者生产了：" i);
}
});
Thread thread2 = new Thread(() -> {
for (int i=0;i<100;i ) {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Object take = yzBlockingQuery.take();
System.out.println("消费者消费了：" take);
}
});
thread1.start();
thread2.start();
}
}