Java中的 BlockingQueue是什么?

java.util.concurrent.BlockingQueue是Qu​​eue的子接口，它支持诸如在插入新值之前等待空间可用性或在从队列中检索元素之前等待队列变为非空之类的操作。考虑以下示例。

import java.util.Random;  
import java.util.concurrent.ArrayBlockingQueue;  
import java.util.concurrent.BlockingQueue;  
  
public class TestThread {  
  
   public static void main(final String[] arguments) throws InterruptedException {  
      BlockingQueue<Integer> queue = new ArrayBlockingQueue<Integer>(10);  
  
      Insert i = new Insert(queue);  
      Retrieve r = new Retrieve(queue);  
  
      new Thread(i).start();  
      new Thread(r).start();  
  
      Thread.sleep(2000);  
   }    
  
  
   static class Insert implements Runnable {  
      private BlockingQueue<Integer> queue;  
  
      public Insert(BlockingQueue queue) {  
         this.queue = queue;  
      }  
  
      @Override  
      public void run() {  
         Random random = new Random();  
  
         try {  
            int result = random.nextInt(200);  
            Thread.sleep(1000);  
            queue.put(result);  
            System.out.println("Added: " + result);  
              
            result = random.nextInt(10);  
            Thread.sleep(1000);  
            queue.put(result);  
            System.out.println("Added: " + result);  
              
            result = random.nextInt(50);  
            Thread.sleep(1000);  
            queue.put(result);  
            System.out.println("Added: " + result);  
         } catch (InterruptedException e) {  
            e.printStackTrace();  
         }  
      }      
   }  
  
   static class Retrieve implements Runnable {  
      private BlockingQueue<Integer> queue;  
  
      public Retrieve(BlockingQueue queue) {  
         this.queue = queue;  
      }  
        
      @Override  
      public void run() {  
           
         try {  
            System.out.println("Removed: " + queue.take());  
            System.out.println("Removed: " + queue.take());  
            System.out.println("Removed: " + queue.take());  
         } catch (InterruptedException e) {  
            e.printStackTrace();  
         }  
      }  
   }  
}