exercise24_1.java

java程序设计 机械工业出版社 书籍代码

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

public class Exercise24_1 extends JApplet {
  // Create four spinners for date, day, month, and year
  private JSpinner spinnerDate =
    new JSpinner(new SpinnerDateModel());
  private JSpinner spinnerDay =
    new JSpinner(new SpinnerNumberModel(1, 1, 31, 1));
  private String[] monthNames = new DateFormatSymbols().getMonths();
  private JSpinner spinnerMonth = new JSpinner
    (new SpinnerListModel(Arrays.asList(monthNames).subList(0, 12)));
  private JSpinner spinnerYear =
    new JSpinner(new SpinnerNumberModel(2004, 1, 3000, 1));

  public Exercise24_1() {
    // Group labels
    JPanel panel1 = new JPanel();
    panel1.setLayout(new GridLayout(4, 1));
    panel1.add(new JLabel("Date"));
    panel1.add(new JLabel("Day"));
    panel1.add(new JLabel("Month"));
    panel1.add(new JLabel("Year"));

    // Group spinners
    JPanel panel2 = new JPanel();
    panel2.setLayout(new GridLayout(4, 1));
    panel2.add(spinnerDate);
    panel2.add(spinnerDay);
    panel2.add(spinnerMonth);
    panel2.add(spinnerYear);

    // Add spinner and label to the UI
    getContentPane().add(panel1, BorderLayout.WEST);
    getContentPane().add(panel2, BorderLayout.CENTER);

    // Set editor for date
    JSpinner.DateEditor dateEditor =
      new JSpinner.DateEditor(spinnerDate, "MMM dd, yyyy");
    spinnerDate.setEditor(dateEditor);

    // Set editor for year
    JSpinner.NumberEditor yearEditor =
      new JSpinner.NumberEditor(spinnerYear, "####");
    spinnerYear.setEditor(yearEditor);

    // Update date to synchronize with the day, month, and year
    updateDate();

    // Register and create a listener for spinnerDay
    spinnerDay.addChangeListener(new ChangeListener() {
      public void stateChanged(javax.swing.event.ChangeEvent e) {
        updateDate();
      }
    });

    // Register and create a listener for spinnerMonth
    spinnerMonth.addChangeListener(new ChangeListener() {
      public void stateChanged(javax.swing.event.ChangeEvent e) {
        updateDate();
      }
    });

    // Register and create a listener for spinnerYear
    spinnerYear.addChangeListener(new ChangeListener() {
      public void stateChanged(javax.swing.event.ChangeEvent e) {
        updateDate();
      }
    });

    // Register and create a listener for spinnerDate
    spinnerDate.addChangeListener(new ChangeListener() {
      public void stateChanged(javax.swing.event.ChangeEvent e) {
        // Get current day, month, and year in int
        int day = ((Date)spinnerDate.getValue()).getDate();
        int month = ((Date)spinnerDate.getValue()).getMonth();
        int year = ((Date)spinnerDate.getValue()).getYear();

        // Set a new date in the date spinner
        System.out.println("day is " + day + " month is " + month +
          " year is " + year);
        spinnerDay.setValue(new Integer(day));
        spinnerMonth.setValue(monthNames[month]);
        spinnerYear.setValue(new Integer(year + 1900));
      }
    });
  }

  // Update date spinner to synchronize with the other three spinners
  private void updateDate() {
    // Get current month and year in int
    int month = ((SpinnerListModel) spinnerMonth.getModel()).
      getList().indexOf(spinnerMonth.getValue());
    int year = ((Integer)spinnerYear.getValue()).intValue();

    // Set a new maximum number of days for the new month and year
    SpinnerNumberModel numberModel =
      (SpinnerNumberModel)spinnerDay.getModel();
    numberModel.setMaximum(new Integer(maxDaysInMonth(year, month)));

    // Set a new current day if it exceeds the maximum
    if (((Integer)(numberModel.getValue())).intValue() >
      maxDaysInMonth(year, month))
      numberModel.setValue(new Integer(maxDaysInMonth(year, month)));

    // Get the current day
    int day = ((Integer)spinnerDay.getValue()).intValue();

    // Set a new date in the date spinner
    spinnerDate.setValue(
      new GregorianCalendar(year, month, day).getTime());
  }

  /** Return the maximum number of days in a month. For example,
    Feb 2004 has 29 days. */
  private int maxDaysInMonth(int year, int month) {
    Calendar calendar = new GregorianCalendar(year, month, 1);
    return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
  }

  public static void main(String[] args) {
    javax.swing.JFrame frame = new javax.swing.JFrame(
        "Exercise24_1");

    Exercise24_1 applet = new Exercise24_1();

    // Add the applet instance to the frame
    frame.getContentPane().add(applet, java.awt.BorderLayout.CENTER);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Invoke init and start
    applet.init();
    applet.start();

    // Display the frame
    frame.pack();
    frame.setVisible(true);
  }
}