java高级---->Thread之BlockingQueue的使用

　　今天我们通过实例来学习一下BlockingQueue的用法。梦想，可以天花乱坠，理想，是我们一步一个脚印踩出来的坎坷道路。

BlockingQueue的实例

官方文档上的对于BlockingQueue的说明：

A Queue that additionally supports operations that wait for the queue to become non-empty when retrieving an element, and wait for space to become available in the queue when storing an element.

如果BlockQueue是空的,从BlockingQueue取东西的操作将会被阻断进入等待状态,直到BlockingQueue进了东西才会被唤醒.同样,如果BlockingQueue是满的,任何试图往里存东西的操作也会被阻断进入等待状态,直到BlockingQueue里有空间才会被唤醒继续操作

一、BlockingQueue的简单使用

package com.linux.huhx.concurreny;

import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.TimeUnit;

public class BlockingQueueTest {
public static void main(String[] args) {
BlockingQueue q = new LinkedBlockingDeque();
Producer p = new Producer(q);
Consumer c1 = new Consumer(q);
Consumer c2 = new Consumer(q);
new Thread(p).start();
new Thread(c1).start();
new Thread(c2).start();
}

static class Producer implements Runnable {
private final BlockingQueue<String> queue;
Producer(BlockingQueue<String> queue) {
this.queue = queue;
}
@Override
public void run() {
for (int i = 0; i < 4; i++) {
try {
queue.put("producer" + i);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}

static class Consumer implements Runnable {
private final BlockingQueue queue;
Consumer(BlockingQueue queue) {
this.queue = queue;
}
public void run() {
for (int i = 0; i < 2; i++) {
try {
TimeUnit.MILLISECONDS.sleep(new Random().nextInt(2000));
System.out.println(queue.take());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}

运行的结果如下：使用put和take方法，打印的结果是固定的。它会阻塞。

producer0
producer1
producer2
producer3

二、ArrayBlockIngQueue的使用

package com.linux.thread.thread;

import org.junit.Test;

import java.util.concurrent.ArrayBlockingQueue;

public class ArrayBlockQueueTest {
@Test
public void put() {
try {
ArrayBlockingQueue<String> queue = new ArrayBlockingQueue<String>(3);
queue.put("huhx");
queue.put("linux");
queue.put("ll");
System.out.println("size: " + queue.size());
System.out.println("begin: " + System.currentTimeMillis());
queue.put("tomhu"); // 阻塞
System.out.println("end: " + System.currentTimeMillis());
} catch (InterruptedException e) {
e.printStackTrace();
}
}

@Test
public void get() {
try {
ArrayBlockingQueue<String> queue = new ArrayBlockingQueue<String>(3);
System.out.println("begin: " + System.currentTimeMillis());
System.out.println(queue.take()); // 阻塞
System.out.println("end: " + System.currentTimeMillis());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

友情链接