Java中的 BlockingDeque removeLastOccurrence() 方法及示例

BlockingDeque的removeLastOccurrence()方法从该双端队列中删除指定元素的最后一次出现。如果双端队列不包含该元素，则它保持不变。如果此双端队列包含指定的元素，则返回 true，否则返回 false。

句法：

public boolean removeLastOccurrence(Object o)

参数：此方法接受一个强制参数o ，该参数指定要从 Dequeue 容器中删除最后一次出现的元素。

返回：如果元素存在并从 Deque 容器中删除，则此方法返回true ，否则返回false 。

注意： BlockingDeque的removeLastOccurrence()方法继承自Java中的 LinkedBlockingDeque 类。

下面的程序说明了 BlockingDeque 的 removeLastOccurrence() 方法：

程序 1：当元素存在时。

// Java Program to demonstrate removeLastOccurrence()
// 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 BD
            = new LinkedBlockingDeque();
  
        // Add numbers to end of BlockingDeque
        BD.add(15);
        BD.add(20);
        BD.add(20);
        BD.add(15);
  
        // print Dequeue
        System.out.println("Blocking Deque: " + BD);
  
        if (BD.removeLastOccurrence(15))
            System.out.println("Last 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]
Last occurrence of 15 removed
Blocking Deque: [15, 20, 20]

程序 2：当元素不存在时。

// Java Program to demonstrate removeLastOccurrence()
// method of BlockingDeque
  
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws InterruptedException
    {
  
        // create object of BlockingDeque
        BlockingDeque BD
            = new LinkedBlockingDeque();
  
        // 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.removeLastOccurrence(10))
            System.out.println("Last 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: Java Java.lang.Object)