Java BlockingDeque removeFirstOccurrence()用法及代码示例

BlockingDeque的removeFirstOccurrence()方法从此双端队列中删除指定元素的首次出现。如果双端队列不包含元素，则它将保持不变。如果此双端队列包含指定的元素，则返回true，否则返回false。

用法:

public boolean removeFirstOccurrence(Object o)

参数：此方法接受必需的参数o，该参数指定要从Deque容器中删除的元素。

返回值：如果该元素存在并且已从Deque容器中删除，则此方法返回true，否则返回false。

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

以下示例程序旨在说明BlockingDeque的removeFirstOccurrence()方法：

示例1:当元素存在时

// Java Program to demonstrate removeFirstOccurrence() 
// 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) 
        throws InterruptedException 
    { 
  
        // create object of BlockingDeque 
        BlockingDeque<Integer> BD 
            = new LinkedBlockingDeque<Integer>(); 
  
        // Add numbers to end of BlockingDeque 
        BD.add(15); 
        BD.add(20); 
        BD.add(20); 
        BD.add(15); 
  
        // print Deque 
        System.out.println("Blocking Deque: " + BD); 
  
        if (BD.removeFirstOccurrence(15)) 
            System.out.println("Fist occurrence of 15 removed"); 
        else
            System.out.println("15 not present and not removed"); 
  
        // prints the Deque after removal 
        System.out.println("Blocking Deque: " + BD); 
    } 
}

输出：

Blocking Deque: [15, 20, 20, 15]
Fist occurrence of 15 removed
Blocking Deque: [20, 20, 15]

示例2:当元素不存在时

// Java Program to demonstrate removeFirstOccurrence() 
// 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) 
        throws InterruptedException 
    { 
  
        // create object of BlockingDeque 
        BlockingDeque<Integer> BD 
            = new LinkedBlockingDeque<Integer>(); 
  
        // Add numbers to end of BlockingDeque 
        BD.add(15); 
        BD.add(20); 
        BD.add(20); 
        BD.add(15); 
  
        // print Deque 
        System.out.println("Blocking Deque: " + BD); 
  
        if (BD.removeFirstOccurrence(10)) 
            System.out.println("Fist occurrence of 10 removed"); 
        else
            System.out.println("10 not present and not removed"); 
  
        // prints the Deque after removal 
        System.out.println("Blocking Deque: " + BD); 
    } 
}

输出：

Blocking Deque: [15, 20, 20, 15]
10 not present and not removed
Blocking Deque: [15, 20, 20, 15]

参考： https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/BlockingDeque.html#removeFirstOccurrence(java.lang.Object)

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 removeFirstOccurrence() 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。