队列阻塞

import java.util.LinkedList;
import java.util.List;


public class BlockingQueue {
private List<Object> queue = new LinkedList<Object>();
private int limit = 10;


public BlockingQueue(int limit) {
this.limit = limit;
}


public synchronized void enqueue(Object item) throws InterruptedException {
while (this.queue.size() == this.limit) { // 注意要使用while循环，而不是if，因为下面的notifyAll可能把正在等待的入队线程给唤醒
wait();
}
if (this.queue.size() == 0) {
notifyAll();
}
System.out.println("enp");
this.queue.add(item);
}


public synchronized Object dequeue() throws InterruptedException {
while (this.queue.size() == 0) {
wait();
}
if (this.queue.size() == this.limit) {
notifyAll();
}


System.out.println("dep");
return this.queue.remove(0);
}


}