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📜  Java中的 LinkedBlockingDeque getLast() 方法

📅  最后修改于: 2022-05-13 01:54:54.620000             🧑  作者: Mango

Java中的 LinkedBlockingDeque getLast() 方法

LinkedBlockingDequegetLast()方法返回 Deque 容器中的最后一个元素。如果 LinkedBlockingDeque 为空,则在函数调用时返回NoSuchElementException

句法:

public E getLast()

参数:此方法不接受任何参数。

返回:此方法返回此 Deque 容器的最后一个元素。

异常:当双端队列为空时,该函数仅抛出一个异常,即NoSuchElementException

下面的程序说明了 LinkedBlockingDeque 的 getLast() 方法:

方案一:

// Java Program Demonstrate getLast()
// method of LinkedBlockingDeque
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque LBD
            = new LinkedBlockingDeque();
  
        // Add numbers to front of LinkedBlockingDeque
        LBD.addFirst(7855642);
        LBD.addFirst(35658786);
        LBD.addFirst(5278367);
        LBD.addFirst(74381793);
  
        // before removing print queue
        System.out.println("Linked Blocking Deque: " + LBD);
  
        // prints the last element
        System.out.println("Linked Blocking Deque first element: " +
                                                     LBD.getLast());
    }
}
输出:
Linked Blocking Deque: [74381793, 5278367, 35658786, 7855642]
Linked Blocking Deque first element: 7855642

方案二:

// Java Program Demonstrate getLast()
// method of LinkedBlockingDeque
// shows exception
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws IllegalStateException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque LBD
            = new LinkedBlockingDeque();
  
        // Add numbers to front of LinkedBlockingDeque
        LBD.addFirst(7855642);
        LBD.addFirst(35658786);
        LBD.addFirst(5278367);
        LBD.addFirst(74381793)
  
            LBD.clear();
  
        // Since the container is empty it will throw exception
        System.out.println("Linked Blocking Deque first element: " + 
                                                     LBD.getLast());
    }
}

输出:

Exception in thread "main" java.util.NoSuchElementException
    at java.util.concurrent.LinkedBlockingDeque.getLast(LinkedBlockingDeque.java:553)
    at GFG.main(GFG.java:28)

参考: https: Java/util/concurrent/LinkedBlockingDeque.html#getLast()