Java 中 LinkedBlockingDeque takeFirst()方法

原文:https://www . geeksforgeeks . org/link edblockingeque-take first-in-method-Java/

takeFirst() 方法将链接锁定请求返回并从其中移除德奎容器的第一个元素,如有必要,等待直到某个元素可用..如果在等待时被中断,该方法将抛出中断异常

语法:

public E takeFirst()

返回:该方法返回德奎容器的第一个元素,如有必要,等待直到某个元素可用。

异常:如果在等待时被中断,该功能会抛出中断异常

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

程序 1:

// 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<Integer> LBD
            = new LinkedBlockingDeque<Integer>();

        // 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: 演示中断异常

// 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<Integer> LBD
            = new LinkedBlockingDeque<Integer>();

        // 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://docs . Oracle . com/javase/8/docs/API/Java/util/concurrent/linkedblockingrequest . html # take first–