Java中的 PriorityBlockingQueue take() 方法

PriorityBlockingQueue的take()方法在移除队列后返回队列的头部。如果队列为空，则此方法将等待直到元素可用。

句法：

public E take() throws InterruptedException

返回：此方法返回此 PriorityBlockingQueue头部的值。

异常：如果在等待元素变为可用时被中断，此方法将抛出InterruptedException 。

下面的程序说明了 PriorityBlockingQueue 的 take() 方法：

示例 1：演示包含数字列表的 PriorityBlockingQueue 上的 take() 方法。

// Java Program Demonstrate take()
// method of PriorityBlockingQueue
  
import java.util.concurrent.PriorityBlockingQueue;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws InterruptedException
    {
  
        // create object of PriorityBlockingQueue
        PriorityBlockingQueue PrioQueue
            = new PriorityBlockingQueue();
  
        // Add numbers to PriorityBlockingQueue
        PrioQueue.put(7855642);
        PrioQueue.put(35658786);
        PrioQueue.put(5278367);
        PrioQueue.put(74381793);
  
        // before removing print queue
        System.out.println("Queue: " + PrioQueue);
  
        // Apply take() method
        int head = PrioQueue.take();
  
        // Print head of queue using take() method
        System.out.println("Head of PriorityBlockingQueue"
                           + " using take(): " + head);
  
        System.out.print("After removing head, Queue: "
                         + PrioQueue);
    }
}

输出：

Queue: [5278367, 35658786, 7855642, 74381793]
Head of PriorityBlockingQueue using take(): 5278367
After removing head, Queue: [7855642, 35658786, 74381793]

示例 2：演示包含 String 的 PriorityBlockingQueue 上的 take() 方法

// Java Program Demonstrate take()
// method of PriorityBlockingQueue
  
import java.util.concurrent.PriorityBlockingQueue;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws InterruptedException
    {
  
        // create object of PriorityBlockingQueue
        // which contains Strings
        PriorityBlockingQueue names
            = new PriorityBlockingQueue();
  
        // Add string
        names.add("Geeks");
        names.add("forGeeks");
        names.add("A computer portal");
  
        // print list of names
        System.out.println(names);
  
        // Apply take() method
        String head = names.take();
  
        // Print head of queue using take() method
        System.out.println("Head of Queue: "
                           + head);
        System.out.print("After removing head, Queue: "
                         + names);
    }
}

输出：

[A computer portal, forGeeks, Geeks]
Head of Queue: A computer portal
After removing head, Queue: [Geeks, forGeeks]

参考： https: Java/util/concurrent/PriorityBlockingQueue.html#take–