写了个桌面的小闹钟,在运行环境可以编译,但是打包成jar文件,想用批处理命令直接调用报错"找不到或无法加载主类".

需求

为防止整天久坐,编写一个桌面闹钟.该闹钟功能很简单,一个小时的倒计时,倒计时结束弹框提示起身运动下.点击确认后重新计时.且有一个复位按钮,可以重新计时.

代码

定义一个1小时的时间变量
创建一个GUI界面,有一个Label标签显示时间,一个Button进行复位操作
计时器每秒判断时间变量是否大于0.大于0减1,否则弹框提示并对时间变量复原
弹框点确认可以实现复位键的同样效果

代码如下:

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingConstants;
import javax.swing.Timer;

public class AlarmClock {

        private static int countdownTime = 60*60 ; //一小时倒计时
	private static int countTime = 0;
	private static JFrame frame;
	private static JLabel timeLabel;
	private static JButton resetButton;
	private static JLabel uptimeLabel;

	public static void main(String[] args) {
		createdUI();
	}
	
	private static void createdUI(){
		frame = new JFrame("电脑桌面闹钟");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setSize(300,200);
		frame.setLayout(new FlowLayout());
		
		timeLabel = new JLabel("剩余时间："+countdownTime/60 +"分钟"+countdownTime%60+"秒;计时:");
		frame.add(timeLabel);
		
		uptimeLabel = new JLabel("00:00:00",SwingConstants.CENTER);
		frame.add(uptimeLabel);
		
		resetButton = new JButton("复位");
		resetButton.addActionListener(new ActionListener() {
	
			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				countdownTime = 60*60 ; // 重新开始一小时计时
				countTime = 0;
				updateTimeLabel();
			}
		});
		frame.add(resetButton);
		
		Timer timer = new Timer(1000,new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				if (countdownTime > 0) {
					countdownTime --;
					countTime++;
					updateTimeLabel();
				}else{
					showDialog(frame);
				}
			}
		});
		timer.start();
		
		frame.setVisible(true);
	}

	
	private static void updateTimeLabel(){
		timeLabel.setText("剩余时间："+countdownTime/60+"分钟"+countdownTime%60+"秒");
		int hours = countTime /3600;
		int minutes = (countTime % 3600)/60;
		int remainingSeconds = countTime % 60;
		uptimeLabel.setText(String.format("%02d:%2d:%2d", hours,minutes,remainingSeconds));
	}
	
	
	private static void showDialog(JFrame parent){
		JDialog jDialog = new JDialog(parent,"确认对话框",true);
		jDialog.setSize(200,100);
		
		JButton okButton = new JButton("确认");
		okButton.addActionListener(new ActionListener() {
			
			@Override
			public void actionPerformed(ActionEvent e) {
				// TODO Auto-generated method stub
				if (e.getSource() == okButton) {
					countdownTime = 60*60  ;
					countTime = 0;
					timeLabel.setText("剩余时间："+countdownTime/60+"分钟"+countdownTime%60+"秒");
					uptimeLabel.setText("00:00:00");
				}
				jDialog.dispose();
			}
		});
		
		JPanel panel = new JPanel();
		panel.add(okButton);
		jDialog.getContentPane().add(panel,BorderLayout.CENTER);
		
		//获取屏幕尺寸和对话框尺寸，计算居中位置
		Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
		int x = (screenSize.width - jDialog.getWidth()) /2 ;
		int y = (screenSize.height - jDialog.getHeight()) / 2;
		//设置对话框位置
		jDialog.setLocation(x,y);
		
		//设置对话框始终位于顶部
		jDialog.setAlwaysOnTop(true);
		//设置对话框为模态对话框
		jDialog.setModal(true);
		
		
		jDialog.setVisible(true);
	}
}