showtimeapp.java

还不错的java基本实例

/*
 * 创建日期 2006-1-24
 *
 * TODO 要更改此生成的文件的模板，请转至
 * 窗口 － 首选项 － Java － 代码样式 － 代码模板
 */
package ch4;

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
import java.text.*;
public class ShowtimeApp extends JFrame{
 private JButton myJButton ;
 private JTextField mytext1;
 private JTextField mytext2;
 private JTextField mytext3;
 private JLabel showlabel;
 private JLabel mylabel1;
 private JLabel mylabel2;
 private JLabel mylabel3;
 
 public ShowtimeApp(){
        createComponents();
        registerEventHandlers();
        layoutComponents(); 
        setTitle("显示时间");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack(); 
 }
 public void createComponents(){
  
  myJButton = new JButton("显示时间");
  mytext1 = new JTextField(6);
  mytext2 = new JTextField(6);
  mytext3 = new JTextField(6);
  mylabel1 = new JLabel("小时");
  mylabel2 = new JLabel("分钟");
  mylabel3 = new JLabel("    秒");
  showlabel = new JLabel("");
 }
 public void registerEventHandlers(){
     myJButtonActionEventHander hander1 = new myJButtonActionEventHander();
     myJButton.addActionListener(hander1);
 }
 public void layoutComponents(){
  
  Container mycontainer = this.getContentPane();
  mycontainer.setLayout(new GridLayout(5, 0,0,-10));
  
  JPanel panel1 = new JPanel();
  panel1.setLayout(new FlowLayout());
  panel1.add(mylabel1);
  panel1.add(mytext1);
  
  JPanel panel2 = new JPanel();
  panel2.setLayout(new FlowLayout());
  panel2.add(mylabel2);
  panel2.add(mytext2);
  
  JPanel panel3 = new JPanel();
  panel3.setLayout(new FlowLayout());
  panel3.add(mylabel3);
  panel3.add(mytext3);
  
  JPanel panel4 = new JPanel();
  panel4.add(showlabel);
  
  JPanel panel5 = new JPanel();
  panel5.add(myJButton);
  
  mycontainer.add(panel1);
  mycontainer.add(panel2);
  mycontainer.add(panel3);
  mycontainer.add(panel4);
  mycontainer.add(panel5);
 }
 
 public class myJButtonActionEventHander implements ActionListener{
  public void actionPerformed(ActionEvent e){
      DecimalFormat twoDigits=new DecimalFormat("00");
      int Hour,Minute,Second;
      Hour =Integer.parseInt(mytext1.getText());
      Minute = Integer.parseInt(mytext2.getText());
      Second = Integer.parseInt(mytext3.getText());
   
      Hour = Hour>=0 & Hour <24?Hour:-1;
      Minute = Minute>=0 & Minute <60?Minute:-1;
      Second = Second>=0 & Second <60?Second:-1;
      if (Hour!=-1 & Minute!=-1 & Second!= -1){
          Hour=(Hour==12 || Hour==0) ? 12:Hour%12;    
          showlabel.setText(Hour+":"+twoDigits.format(Minute)+":"+
                  twoDigits.format(Second)+"   "+(Hour<12?"AM":"PM"));
       }
      else   
       JOptionPane.showMessageDialog( null,
              "你输入的时间不正确，请重新输入",
                    "错误消息",+JOptionPane.INFORMATION_MESSAGE);
  }
 }
 
 public static void main(String[] args){

        JFrame.setDefaultLookAndFeelDecorated(true);
        ShowtimeApp frame= new ShowtimeApp();
        frame.setVisible(true);
    }
}