线程不会在Java上启动

Question

The following code should produce a regular frame with time in it, when the time hit 90 minutes it should display a message. somehow the Thread wont start and the message Thread is working properly is never displayed. i have already read the following Oracle article but couldn't find any solution.

public class Core extends JFrame implements Runnable{

private int second;
private int minute;
private JLabel presentor;
private Thread threadObject = new Thread();

public Core(){
    second = 1;
    minute = 0;
    presentor = new JLabel();
    writeLabel();
    add(presentor , BorderLayout.CENTER);
    threadObject.start();
}

public void run(){
    JOptionPane.showMessageDialog(null, "Thread is working properly");
    try{Thread.sleep(60000);}
    catch(InterruptedException e){e.printStackTrace();}
    updateTime();
    writeLabel();
    if(minute > 89){
        JOptionPane.showMessageDialog(null, "90 minutes have passed away , take a break!");
        this.getParent().setFocusable(true);
    }
}

public void writeLabel(){
    presentor.setText(minute + ":" + second);
}

public void updateTime(){
    second++;
    if(second < 60)
        return;
    second = 0;
    minute++;

}

}

there is also a class with the Main method which have the basic frame setting, nothing important there.

Answer 1

您没有为Thread指定Runnable参数（由于核心类实现了Runnable ，因此我认为应该是this参数）：

private Thread threadObject = new Thread(this);

Answer 2

TNT's answer is correct, but it's not complete. Your program has more than one problem. The next problem you will face is that there's no loop in your run() method. It will call updateTime() and writeLabel() exactly once, and then the thread will terminate.

The next problem after that, is in your updateTime() method. It appears as if it's meant to count seconds, but your run() method looks like, if it had a loop, it would only call updateTime() once every minute. That means it will take 90 HOURS, not 90 minutes before your program pops up the dialogue.