嘗試對計時器進行編程，以便用戶只能輸入一定時間的單詞

Question

我正在嘗試制作一個只能輸入單詞10秒鍾的游戲。 我試圖創建一個多線程解決方案，但無法正常工作。

class timer extends Thread{//thread
public void run(){
    for(int i=10;i>=0;i--){
        System.out.print(i+" ");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}
}

主要方法：

            timer t=new timer();
            t.start();
            while () {//not sure what to put in my while statement
                System.out.print("Guess a word on the board! ");
                if(test.CheckGame(scan.next())==true){
                    System.out.print("Good job! ");
                }
                else    
                    System.out.print("Guess again! ");
            }

本質上，線程運行10秒鍾並終止后，我希望它返回一個break語句，以便程序退出while循環。 有什么建議么？

Answer 1

將您的代碼更改為此

timer t=new timer();
t.start();
while (t.isAlive()) {//not sure what to put in my while statement
    System.out.print("Guess a word on the board! ");
    if(test.CheckGame(scan.next())==true){
        System.out.print("Good job! ");
    }
    else    
        System.out.print("Guess again! ");
}

運行函數退出后，t.isAlive將為false。 您可能還需要傳遞計時器對象，並檢查對象的isAlive（），具體取決於CheckGame的工作方式。 這樣一來，在10秒鍾后不能無限期地輸入輸入。

Answer 2

這是一個簡單的演示，它將使您知道如何使用java.util.Timer 。

import java.util.Timer;
import java.util.TimerTask;
import java.util.Scanner;
class Tester 
{
    static long i = 0;
    public static void main(String[] args) throws Exception
    {
        Scanner scanner = new Scanner(System.in);
        System.out.println("You have only 10 seconds to find the result");
        System.out.println("What is the value of : 111111 X 111111 ");
        Timer timer = new Timer("Timer");
        timer.schedule(new TimerTask()
        {
            public void run()
            {
                if (i == 12345654321L)
                {
                    System.out.println("Congrats!! you guessed the write answer :)");
                }
                else
                {
                    System.out.println("Sorry Time is over. You couldn't guess the correct answer.");
                }
                System.exit(0);
            }
        },10 * 1000 , 1);
        while (true)
        {
            i = scanner.nextLong(); 
            if ( i == 12345654321L)
            {
                System.out.println("Congrats!! you guessed the write answer :)");
                System.exit(0);
            }
            else
            {
                System.out.println("Try next  guess :");
            }
        }
    }
}

編輯

由於我沒有您的全部代碼，因此我將在此處發布基於我的基本假設的答案的解決方案。 不要使用線程。 而是使用java.util.Timer 。 您的代碼如下所示：

static String input=" ";//created a static variable input to take input 
public static void main(String st[])
{
    Timer timer = new Timer("Timer");
    timer.schedule(new TimerTask()
    {
        public void run()
        {
            if (test.CheckGame(input))
            {
                System.out.println("Congrats!! you guessed the write answer :)");
            }
            else
            {
                System.out.println("Sorry Time is over. You couldn't guess the correct answer.");
            }
            System.exit(0);
        }
    },10 * 1000 , 1);//waits for 10 seconds
    while (true) 
    {
        System.out.print("Guess a word on the board! ");
        input = scan.next();
        if(test.CheckGame(input))
        {
            System.out.print("Good job! ");
            System.exit(0);
        }
        else
        {
            System.out.println("Bad Guess. Try again ");
        }
    }
}

Answer 3

您可以有一個共享的布爾值，您的線程和主線程以同步方式共享。

計時器可以如下：

class timer extends Thread{//thread
private Object lock = new Object(); // a lock used by both your thread and main to access stop boolean
private boolean stop = false;
public void setStop() // your thread calls this method in order to set stop
{
   synchronized(lock) {
   stop = true;
   }
}

public boolean getStop() // main calls this to see if thread told main to stop.
{
   boolean _stop;
   synchronized(lock) {
   _stop = stop;
   }
   return _stop;
}
public void run(){
    for(int i=10;i>=0;i--){
        System.out.print(i+" ");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        setStop();
    }
}
}

您的主要內容可能如下：

timer t=new timer();
            t.start();
            while (!t.getStop()) {// calls getStop to see if other thread told main to stop
                System.out.print("Guess a word on the board! ");
                if(test.CheckGame(scan.next())==true){
                    System.out.print("Good job! ");
                }
                else    
                    System.out.print("Guess again! ");
            }
            t.join(); // to make sure main terminates after the termination of other thread