java - 尝试使用线程时程序锁定

Question

这是我在这里发表的第一篇文章，希望一切顺利。

我在 netbeans。我制作了一个带有按钮等的窗口。

我有一个名为 SimpleThread 的类，如下所示:

public class SimpleThread extends Thread {

public SimpleThread()
{

}

@Override
public void run()
{

}

我有不同类型的子类线程，它们扩展了简单线程(TimerThread、MouseGrabThread)。

public class MouseGrabThread extends SimpleThread{

private Point pt;
private JTextField x, y;

public MouseGrabThread(JTextField x, JTextField y)
{
    super();
    this.x = x; 
    this.y = y;
}

@Override
public void run()
{
    while(this.isAlive())
    {
        int[] xyVal = new int[2];
        xyVal = getCoords();
        x.setText("" + xyVal[0]);
        y.setText("" + xyVal[1]);
    }
}

public int[] getCoords()
{
    Point pt = MouseInfo.getPointerInfo().getLocation();

    int[] retArr = new int[2];
    retArr[0] = (int)pt.getX();
    retArr[1] = (int)pt.getY();

    return retArr;

}



public class TimerThread extends SimpleThread {

private JTextArea label;
private int time;

public TimerThread(JTextArea label, int time)
{
    super();
    this.label = label;
    this.time = time;
}

@Override
public void run()
{
    int counter = time;
    while(counter != -1)
    {

        label.setText("You have: " + counter + " seconds until the timer ends!\n");
        counter--;
        try {
            this.sleep(1000);
        } catch (InterruptedException ex) {
            System.out.println("Thread Interrupted");
        }

    }
    stop();
}

在我的 UI Window 类中，我有这个:

private void jButton2MouseClicked(java.awt.event.MouseEvent evt) {                                      
   SimpleThread timer = new TimerThread(jTextArea1, 10); //This counts down from 10 seconds and updates a status text box each second
   SimpleThread mouseGrab = new MouseGrabThread(jTextField1, jTextField2); //This grabs mouse coords and updates two boxes in the UI.
   timer.start();
   if(timer.isAlive())
   {
      mouseGrab.start();
   }
   while(timer.isAlive())//######
   {
       if(!mouseGrab.isAlive())
       {
           mouseGrab.start();
       }
   }
}           

当我按下按钮时，程序卡住了 10 秒。

我猜我标记的行 (//#####) 是导致 UI 在计时器持续时间内卡住的行，因为它在主线程中运行。我不知道如何纠正这个问题。

请原谅我缺乏编程知识，我现在正在自己进入线程，同时我正在大学学习一门非常简单的数据结构类(class)。如果可能的话，你能把答案尽可能地“简化”吗？

另外，我知道我这样做很糟糕，但我调用了 stop() 函数，尽管它不太好(不要向我开枪，我不知道还能怎么做!)如果有人可以为我回答这个问题，告诉我如何做得更好，那就太好了!

Answer 1

您可能想要的是在倒计时结束时结束 mouseGrab:

private void jButton2MouseClicked(java.awt.event.MouseEvent evt) {                                      
   SimpleThread timer = new TimerThread(jTextArea1, 10); //This counts down from 10 seconds and updates a status text box each second
   SimpleThread mouseGrab = new MouseGrabThread(jTextField1, jTextField2); //This grabs mouse coords and updates two boxes in the UI.

   mouseGrab.start();
   timer.start();

   // Wait until countdown finishes
   while(timer.isAlive()) {}

   mouseGrab.stop();
}

在您粘贴的代码中，您在 timer 运行时不断启动 mouseGrab。您可能更希望在计时器打开时让鼠标抓取运行。

编辑:确实，stop() 已被弃用，您确实应该在 TimerThread 中使用 boolean running 属性，并将其 run() 方法的内容包装在某些

while (running) {
    /* stuff */
}

然后用一些 setter 从外部“停止”这个线程。正确答案例如:

   mouseGrab.start();
   timer.start();

   // Wait until countdown finishes
   while(timer.isAlive()) {}

   mouseGrab.setRunning(false);
}

Edit2:这最终似乎就是你想要的:

private void jButton2MouseClicked(java.awt.event.MouseEvent evt) {                                      
   SimpleThread mouseGrab = new MouseGrabThread(jTextField1, jTextField2); //This grabs mouse coords and updates two boxes in the UI.
   SimpleThread timer = new TimerThread(mouseGrab, jTextArea1, 10); //This counts down from 10 seconds and updates a status text box each second

   mouseGrab.start();
   timer.start();
}

与:

public class MouseGrabThread extends SimpleThread {

    private Point pt;
    private JTextField x, y;
    private boolean running;

    public MouseGrabThread(JTextField x, JTextField y) {
        super();
        this.x = x; 
        this.y = y;
    }

    @Override
    public void run() {
        running = true;
        while(running) {
            int[] xyVal = new int[2];
            xyVal = getCoords();
            x.setText("" + xyVal[0]);
            y.setText("" + xyVal[1]);
        }
    }

    public int[] getCoords() {
        Point pt = MouseInfo.getPointerInfo().getLocation();

        int[] retArr = new int[2];
        retArr[0] = (int)pt.getX();
        retArr[1] = (int)pt.getY();

        return retArr;

    }

    public void break() {
        this.running = false;
    }
}


// ------------- //


public class TimerThread extends SimpleThread {

    private MouseGrabThread mouseGrab;
    private JTextArea label;
    private int time;

    public TimerThread(MouseGrabThread mouseGrab, JTextArea label, int time)
    {
        super();
        this.label = label;
        this.time = time;
        this.mouseGrab = mouseGrab;
    }

    @Override
    public void run()
    {
        int counter = time;
        while(counter != -1)
        {
            label.setText("You have: " + counter + " seconds until the timer ends!\n");
            counter--;
            try {
                this.sleep(1000);
            } catch (InterruptedException ex) {
                System.out.println("Thread Interrupted");
            }

        }

        mouseGrab.break();
    }
}