dayoftheweekservice.java

HeadFirstCode系列图书里的源代码

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.io.*;
import java.util.*;
import java.text.*;

public class DayOfTheWeekService implements Service {

    JLabel outputLabel;
    JComboBox month;
    JTextField day;
    JTextField year;

    public JPanel getGuiPanel() {
       JPanel panel = new JPanel();
       JButton button = new JButton("Do it!");
       button.addActionListener(new DoItListener());
       outputLabel = new JLabel("date appears here");
       
       DateFormatSymbols dateStuff = new DateFormatSymbols();      
       month = new JComboBox(dateStuff.getMonths());
       day = new JTextField(8);
       year = new JTextField(8);

       JPanel inputPanel = new JPanel(new GridLayout(3,2));
       inputPanel.add(new JLabel("Month"));
       inputPanel.add(month);
       inputPanel.add(new JLabel("Day"));
       inputPanel.add(day);
       inputPanel.add(new JLabel("Year"));    
       inputPanel.add(year);

       panel.add(inputPanel);
       panel.add(button);
       panel.add(outputLabel);
       return panel;
    }

   public class DoItListener implements ActionListener {
      public void actionPerformed(ActionEvent ev) {
           int monthNum = month.getSelectedIndex(); 
           int dayNum = Integer.parseInt(day.getText());
           int yearNum = Integer.parseInt(year.getText());
           Calendar c = Calendar.getInstance();
           c.set(Calendar.MONTH, monthNum);
           c.set(Calendar.DAY_OF_MONTH, dayNum);
           c.set(Calendar.YEAR, yearNum);
           Date date = c.getTime();
           String dayOfWeek = (new SimpleDateFormat("EEEE")).format(date);
           outputLabel.setText(dayOfWeek);
           
               
      }
    }
       
}