Java BlockingDeque removeLastOccurrence()方法及示例

BlockingDeque 的 removeLastOccurrence() 方法会从这个deque中删除最后出现的指定元素。如果该deque不包含该元素，它将保持不变。如果这个deque包含指定的元素，则返回true，否则返回false。

语法

public boolean removeLastOccurrence(Object o)

参数： 该方法接受一个强制参数 o ，指定最后出现的元素要从Dequeue容器中删除。

返回： 如果该元素存在并从Deque容器中删除，该方法返回 true ，否则返回 false。

注意 ： BlockingDeque 的 removeLastOccurrence() 方法是继承自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<Integer> BD            = new LinkedBlockingDeque<Integer>();          // 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 removedBlocking 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<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.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 removedBlocking Deque: [15, 20, 20, 15]

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