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📜  Java中的 LinkedBlockingDeque takeFirst() 方法

📅  最后修改于: 2022-05-13 01:55:02.672000             🧑  作者: Mango

Java中的 LinkedBlockingDeque takeFirst() 方法

LinkedBlockingDeque 的takeFirst ()方法返回并从中删除 Deque 容器的第一个元素,如果需要,则等待直到元素可用。如果在等待时被中断,该方法将抛出InterruptedException

句法:

public E takeFirst()

返回:此方法返回 Deque 容器的第一个元素,必要时等待,直到元素可用。

Exception :如果函数在等待时被中断,则会抛出InterruptedException

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

方案一:

// Java Program to demonstrate takeFirst()
// method of LinkedBlockingDeque
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws InterruptedException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque LBD
            = new LinkedBlockingDeque();
  
        // Add numbers to end of LinkedBlockingDeque
        LBD.add(7855642);
        LBD.add(35658786);
        LBD.add(5278367);
        LBD.add(74381793);
  
        // print Dequeue
        System.out.println("Linked Blocking Deque: " + LBD);
  
        // removes the front element and prints it
        System.out.println("Head of Linked Blocking Deque: "
                           + LBD.takeFirst());
  
        // prints the Deque
        System.out.println("Linked Blocking Deque: " + LBD);
    }
}
输出:
Linked Blocking Deque: [7855642, 35658786, 5278367, 74381793]
Head of Linked Blocking Deque: 7855642
Linked Blocking Deque: [35658786, 5278367, 74381793]

程序2:演示InterruptedException

// Java Program to demonstrate takeFirst()
// method of LinkedBlockingDeque
  
import java.util.concurrent.LinkedBlockingDeque;
import java.util.*;
  
public class GFG {
    public static void main(String[] args)
        throws InterruptedException
    {
  
        // create object of LinkedBlockingDeque
        LinkedBlockingDeque LBD
            = new LinkedBlockingDeque();
  
        // Add numbers to end of LinkedBlockingDeque
        LBD.add(7855642);
        LBD.add(35658786);
        LBD.add(5278367);
        LBD.add(74381793);
  
        // print Dequeue
        System.out.println("Linked Blocking Deque: " + LBD);
  
        LBD.clear();
  
        // throws error as the list is empty and it
        // is interrupted while waiting
        System.out.println("Head of Linked Blocking Deque: "
                           + LBD.takeFirst());
    }
}

运行时错误:

Max real time limit exceeded due to either by heavy load on server or by using sleep function

参考: https: Java/util/concurrent/LinkedBlockingDeque.html#takeFirst–