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();    }}