Question

用java编写一个计数器或计时器

要可以设置计数或计时的时间间隔、实现开始、停止功能，要用到Thread

Answer 1

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class TimerDemo extends JFrame implements ActionListener {

    private static final long serialVersionUID = 201306211111L;
    private JTextField screen = new JTextField("0");
    private JButton start = new JButton("开始");
    private JButton reset = new JButton("重置");
    private JPanel panel = new JPanel();
    private boolean isRunning;
    private int time;
    private int timeBetween;

    public TimerDemo(int timeBetween) {
        super("计时器");
        this.timeBetween = timeBetween;
        try {
            init();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public TimerDemo() {
        super("计时器");
        this.timeBetween = 100;
        try {
            init();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    private void init() {

        panel.setLayout(new GridLayout());
        panel.add(start);
        panel.add(reset);
        start.addActionListener(this);
        reset.addActionListener(this);
        screen.setFont(new Font("幼圆", Font.BOLD, 60));
        screen.setHorizontalAlignment(JTextField.CENTER);
        screen.setEditable(false);

        Container c = getContentPane();
        c.setLayout(new BorderLayout());
        c.add(panel, BorderLayout.SOUTH);
        c.add(screen, BorderLayout.CENTER);

        this.setSize(200, 150);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setResizable(false);
        this.setLocationRelativeTo(null);
        this.setVisible(true);
    }

    public static void main(String[] args) {
        new TimerDemo(1);// 设定 1ms/次
        // new TimerDemo();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == start) {
            if (start.getText().equals("开始")) {
                start.setText("暂停");
                isRunning = true;
            } else if (start.getText().equals("暂停")) {
                start.setText("开始");
                isRunning = false;
            }

        }
        if (e.getSource() == reset) {
            start.setText("开始");
            screen.setText("0");
            isRunning = false;
            time = 0;
        }
        new Thread(new TimeZone()).start();
    }

    class TimeZone implements Runnable {

        @Override
        public void run() {
            while (isRunning) {
                time++;
                if (time >= Integer.MAX_VALUE) {
                    screen.setText("ERROR");
                    JOptionPane.showMessageDialog(null, "ERROR");
                    isRunning = false;
                }
                screen.setText(String.valueOf(time));
                try {
                    Thread.sleep(timeBetween);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }

    }

}

Answer 2

import java.io.IOException;
import java.util.Timer;
public class TimerTest {
public static void main(String[] args){
Timer timer = new Timer();
timer.schedule(new MyTask(), 1000, 2000);//在1秒后执行此任务,每次间隔2秒,如果传递一个Data参数,就可以在某个固定的时间执行这个任务.
while(true){//这个是用来停止此任务的,否则就一直循环执行此任务了
try {
int ch = System.in.read();
if(ch-'c'==0){
timer.cancel();//使用这个方法退出任务
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
static class MyTask extends java.util.TimerTask{
@Override
public void run() {
//你要进行的操作
}
}
}