当前位置: 首页>>代码示例 >>用法及示例精选 >>正文


Java BlockingDeque pollLast()用法及代码示例


BlockingDeque的pollLast()方法返回Deque容器中的最后一个元素,并将其删除。如果容器为空,则返回null。

用法:

public E pollLast()

参数:此方法不接受任何参数。


返回值:如果容器不为空,则此方法返回Deque容器中的最后一个元素,并删除该元素。如果容器为空,则返回null。

注意:BlockingDeque的pollLast()方法已从Java中的LinkedBlockingDeque类继承。

以下示例程序旨在说明BlockingDeque的pollLast()方法:

示例1:

// Java Program Demonstrate pollLast() 
// method of BlockingDeque 
  
import java.util.concurrent.LinkedBlockingDeque; 
import java.util.concurrent.BlockingDeque; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
  
    { 
  
        // create object of BlockingDeque 
        BlockingDeque<Integer> BD 
            = new LinkedBlockingDeque<Integer>(); 
  
        // Add numbers to end of BlockingDeque 
        BD.addFirst(7855642); 
        BD.addFirst(35658786); 
        BD.addFirst(5278367); 
        BD.addFirst(74381793); 
  
        // Print the queue 
        System.out.println("Blocking Deque: " + BD); 
  
        // prints and deletes the last element 
        System.out.println("Front element in Deque: " + BD.pollLast()); 
  
        // prints the Deque after deletion of last element 
        System.out.println("Blocking Deque: " + BD); 
    } 
}
输出:
Blocking Deque: [74381793, 5278367, 35658786, 7855642]
Front element in Deque: 7855642
Blocking Deque: [74381793, 5278367, 35658786]

示例2:

// Java Program Demonstrate pollLast() 
// method of BlockingDeque 
// when Deque is empty 
  
import java.util.concurrent.LinkedBlockingDeque; 
import java.util.concurrent.BlockingDeque; 
import java.util.*; 
  
public class GFG { 
    public static void main(String[] args) 
  
    { 
  
        // create object of BlockingDeque 
        BlockingDeque<Integer> BD 
            = new LinkedBlockingDeque<Integer>(); 
  
        // Add numbers to end of BlockingDeque 
        BD.add(7855642); 
        BD.add(35658786); 
        BD.add(5278367); 
        BD.add(74381793); 
  
        // Print the queue 
        System.out.println("Blocking Deque: " + BD); 
  
        // empty deque 
        BD.clear(); 
  
        System.out.println("Front element in Deque: " + BD.pollLast()); 
    } 
}
输出:
Blocking Deque: [7855642, 35658786, 5278367, 74381793]
Front element in Deque: null

参考: https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/BlockingDeque.html#pollLast(long, %20java.util.concurrent.TimeUnit)



相关用法


注:本文由纯净天空筛选整理自gopaldave大神的英文原创作品 BlockingDeque pollLast() method in Java with examples。非经特殊声明,原始代码版权归原作者所有,本译文未经允许或授权,请勿转载或复制。