Java多线程-阻塞队列

阻塞队列

• BlockingQueue的核心方法：

  • put(anObject): 将参数放入队列，如果放不进去会阻塞
  • take(): 取出第一个数据，取不到会阻塞

• 常见的BlockingQueue

  • ArrayBlockingQueue：底层是数组，有界
  • LinkedBlockingQueue：底层是链表，无界。但不是真正的无界，最大为int的最大值

阻塞队列的基本写法

package com.cmy.threaddemo11;

import java.util.concurrent.ArrayBlockingQueue;

/**
 * @author 陈明勇
 */
public class Demo {
    public static void main(String[] args) throws InterruptedException {
        // 阻塞队列的基本用法
        // 创建阻塞队列的对象，容量为1
        ArrayBlockingQueue<String> arrayBlockingQueue = new ArrayBlockingQueue<>(1);

        // 存储元素
        arrayBlockingQueue.put("披萨");

        // 取元素
        System.out.println(arrayBlockingQueue.take());
        // 取不到第二个元素，会阻塞
        System.out.println(arrayBlockingQueue.take());
    }
}

ArrayBlockingQueue<String> arrayBlockingQueue = new ArrayBlockingQueue<>(1); 传入的参数1表示容量为1

实现等待唤醒机制

• 生产者

  package com.cmy.threaddemo12;
  
  import java.util.concurrent.ArrayBlockingQueue;
  
  /**
   * @author 陈明勇
   */
  public class Cooker extends Thread{
      private ArrayBlockingQueue<String> arrayBlockingQueue;
  
      public Cooker(ArrayBlockingQueue<String> arrayBlockingQueue) {
          this.arrayBlockingQueue = arrayBlockingQueue;
      }
  
      @Override
      public void run() {
          while (true) {
              try {
                  arrayBlockingQueue.put("披萨");
                  System.out.println("厨师放了一个披萨");
              } catch (InterruptedException e) {
                  e.printStackTrace();
              }
          }
      }
  }
  
  

• 消费者

  package com.cmy.threaddemo12;
  
  import java.util.concurrent.ArrayBlockingQueue;
  
  /**
   * @author 陈明勇
   */
  public class Foodie extends Thread{
      private ArrayBlockingQueue<String> arrayBlockingQueue;
  
      public Foodie(ArrayBlockingQueue<String> arrayBlockingQueue) {
          this.arrayBlockingQueue = arrayBlockingQueue;
      }
  
      @Override
      public void run() {
          String take = null;
          while (true) {
              try {
                  take = arrayBlockingQueue.take();
                  System.out.println("吃货从队列中获取了一个" + take);
              } catch (InterruptedException e) {
                  e.printStackTrace();
              }
          }
      }
  }
  
  

• 测试类

  package com.cmy.threaddemo12;
  
  import java.util.concurrent.ArrayBlockingQueue;
  
  /**
   * @author 陈明勇
   */
  public class Demo {
      public static void main(String[] args) {
          // 创建阻塞队列
          ArrayBlockingQueue<String> arrayBlockingQueue = new ArrayBlockingQueue<>(1);
  
          // 创建线程并开启
          Cooker cooker = new Cooker(arrayBlockingQueue);
          Foodie foodie = new Foodie(arrayBlockingQueue);
          cooker.start();
          foodie.start();
      }
  }
  
  
          Foodie foodie = new Foodie(arrayBlockingQueue);
          cooker.start();
          foodie.start();
      }
  }