blockingqueue的功能和使用

BlockingQueue也是java.util.concurrent下的主要用来控制线程同步的工具。 主要的方法是：put、take一对阻塞存取；add、poll一对非阻塞存取。 插入: 1)add(anObject):把anObject加到BlockingQueue里,即如果BlockingQueue可以容纳,则返回true,否则抛出异常,不好 2)offer(anObject):表示如果可能的话,将anObject加到BlockingQueue里,即如果BlockingQueue可以容纳,则返回true,否则返回false. 3)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, 有阻塞, 放不进去就等待 读取： 4)poll(time):取走BlockingQueue里排在首位的对象,若不能立即取出,则可以等time参数规定的时间,取不到时返回null; 取不到返回null 5)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Blocking有新的对象被加入为止; 阻塞, 取不到就一直等 其他 int remainingCapacity();返回队列剩余的容量，在队列插入和获取的时候，不要瞎搞，数 据可能不准, 不能保证数据的准确性 boolean remove(Object o); 从队列移除元素，如果存在，即移除一个或者更多，队列改 变了返回true public boolean contains(Object o); 查看队列是否存在这个元素，存在返回true int drainTo(Collection

package cn.itcast_02_blockingqueue.producer; import java.util.concurrent.BlockingQueue; public class Producer implements Runnable { BlockingQueue<String> queue; public Producer(BlockingQueue<String> queue) { this.queue = queue; } @Override public void run() { try { System.out.println("I have made a product:" + Thread.currentThread().getName()); String temp = "A Product, 生产线程：" + Thread.currentThread().getName(); queue.put(temp);//如果队列是满的话，会阻塞当前线程 } catch (InterruptedException e) { e.printStackTrace(); } } }

消费者代码实现：

package cn.itcast_02_blockingqueue.consumer; import java.util.concurrent.BlockingQueue; public class Consumer implements Runnable{ BlockingQueue<String> queue; public Consumer(BlockingQueue<String> queue){ this.queue = queue; } @Override public void run() { try { String consumer = Thread.currentThread().getName(); System.out.println(consumer); String temp = queue.take();//如果队列为空，会阻塞当前线程 System.out.println(consumer+"get a product:"+temp); } catch (InterruptedException e) { e.printStackTrace(); } } }

测试类：

package cn.itcast_02_blockingqueue.main; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; import cn.itcast_02_blockingqueue.consumer.Consumer; import cn.itcast_02_blockingqueue.producer.Producer; public class Test { public static void main(String[] args) throws Exception { BlockingQueue<String> queue = new LinkedBlockingQueue<String>(2); // BlockingQueue<String> queue = new LinkedBlockingQueue<String>(); // 不设置的话，LinkedBlockingQueue默认大小为Integer.MAX_VALUE // BlockingQueue<String> queue = new ArrayBlockingQueue<String>(2); Consumer consumer = new Consumer(queue); Producer producer = new Producer(queue); for (int i = 0; i < 3; i++) { new Thread(producer, "Producer" + (i + 1)).start(); } for (int i = 0; i < 5; i++) { new Thread(consumer, "Consumer" + (i + 1)).start(); } new Thread(producer, "Producer" + (5)).start(); } }

blockingqueue生产者代码实现：

package cn.itcast_02_blockingqueue.main; import java.util.Random; import java.util.concurrent.BlockingQueue; public class TestBlockingQueueProducer implements Runnable { BlockingQueue<String> queue; Random random = new Random(); public TestBlockingQueueProducer(BlockingQueue<String> queue) { this.queue = queue; } @Override public void run() { for (int i = 0; i < 10; i++) { try { Thread.sleep(random.nextInt(10)); String task = Thread.currentThread().getName() + " made a product " + i; System.out.println(task); queue.put(task); } catch (InterruptedException e) { e.printStackTrace(); } } } }

blockingqueue消费者代码实现：

package cn.itcast_02_blockingqueue.main; import java.util.Random; import java.util.concurrent.BlockingQueue; public class TestBlockingQueueConsumer implements Runnable{ BlockingQueue<String> queue; Random random = new Random(); public TestBlockingQueueConsumer(BlockingQueue<String> queue){ this.queue = queue; } @Override public void run() { try { Thread.sleep(random.nextInt(10)); System.out.println(Thread.currentThread().getName()+ "trying..."); String temp = queue.take();//如果队列为空，会阻塞当前线程 System.out.println(Thread.currentThread().getName() + " get a job " +temp); } catch (InterruptedException e) { e.printStackTrace(); } } }

blockingqueue测试类：

package cn.itcast_02_blockingqueue.main; import java.util.concurrent.BlockingQueue; import java.util.concurrent.LinkedBlockingQueue; public class TestBlockingQueue { public static void main(String[] args) { BlockingQueue<String> queue = new LinkedBlockingQueue<String>(2); // BlockingQueue<String> queue = new LinkedBlockingQueue<String>(); // 不设置的话，LinkedBlockingQueue默认大小为Integer.MAX_VALUE // BlockingQueue<String> queue = new ArrayBlockingQueue<String>(2); TestBlockingQueueConsumer consumer = new TestBlockingQueueConsumer(queue); TestBlockingQueueProducer producer = new TestBlockingQueueProducer(queue); for (int i = 0; i < 3; i++) { new Thread(producer, "Producer" + (i + 1)).start(); } for (int i = 0; i < 5; i++) { new Thread(consumer, "Consumer" + (i + 1)).start(); } new Thread(producer, "Producer" + (5)).start(); } }