这个是一个实现时间选着的级联下拉选择框(包括年月日)，其中涉及到了闰年2月份天数的处理！

源代码：

package com.blue411;

import java.awt.Dimension;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JComboBox;

import java.awt.*;

import javax.swing.JLabel;

import java.awt.event.ItemEvent;

import java.awt.event.ItemListener;

public class YearMonthDay extends JFrame {

private final int STARTYEAR =

2000;//年份的开始值

private final int ENDYEAR = 2020;//年份的结束值

JPanel contentPane;

//年月日的选择框

JComboBox cboYear = new

JComboBox(); JComboBox cboMonth = new JComboBox();

JComboBox cboDay = new JComboBox();

//年月日标签

JLabel jLabel1 = new JLabel();

JLabel jLabel2 = new JLabel();

JLabel jLabel3 = new JLabel();

public YearMonthDay() {

setDefaultCloseOperation(EXIT_ON_CLOSE);

jbInit();

}

private void jbInit(){

contentPane = (JPanel)

getContentPane();

contentPane.setLayout(null);

setSize(new Dimension(400,

300));

setTitle("年月日下拉列表级联");

// 年的下拉选择框

cboYear.setFont(new

java.awt.Font("Dialog", Font.BOLD, 13));

cboYear.setBounds(new

Rectangle(0, 0, 55, 18));

// 月的下拉选择框

cboMonth.setFont(new

java.awt.Font("Dialog", Font.BOLD, 13));

cboMonth.setBounds(new

Rectangle(80, 0, 45, 18));

cboMonth.addItemListener(new

DateItemAdapter(this));

// 日的下拉选择框

cboDay.setFont(new

java.awt.Font("Dialog", Font.BOLD, 13));

cboDay.setBounds(new

Rectangle(150, 0, 45, 18));

//

cboDay.setEditable(true);

// 年的label

jLabel3.setFont(new

java.awt.Font("Dialog", Font.BOLD, 15));

jLabel3.setText("年");

jLabel3.setBounds(new

Rectangle(60, 0, 20, 20));

// 月的label

jLabel2.setFont(new

java.awt.Font("Dialog", Font.BOLD, 15));

jLabel2.setText("月");

jLabel2.setBounds(new

Rectangle(130, 0, 20, 20));

// 日的label

jLabel1.setFont(new

java.awt.Font("Dialog", Font.BOLD, 15));

jLabel1.setText("日");

jLabel1.setBounds(new

Rectangle(200, 0, 20, 20));

contentPane.add(cboYear);

contentPane.add(cboMonth);

contentPane.add(cboDay);

contentPane.add(jLabel3);

contentPane.add(jLabel2);

contentPane.add(jLabel1);

//添加初始值

AddInfo();

}

private void AddInfo() {

//年下拉选择框

for (int i = STARTYEAR; i

< ENDYEAR; i++) {

cboYear.addItem(""

+ i);

}

//月下拉选择框

for (int i = 0; i

< 12; i++) {

cboMonth.addItem(""

+ (i + 1));

}

//日下拉选择框

for (int j = 0; j

< 31; j++) {

cboDay.addItem(""

+ (j + 1));

}

}

public void

cboMonth_itemStateChanged(ItemEvent e) {

Object obj =

cboMonth.getSelectedItem();// 取得选中月份

if (obj != null)

{ cboDay.removeAllItems();//

清空日的下拉列表框

int month =

Integer.valueOf(obj.toString());

int days =

31;

if (month ==

4 || month == 6 || month == 9 || month == 11) {

days

= 30;

} else if

(month == 2) {

//取得选中年份

int

year = Integer.parseInt(cboYear.getSelectedItem()

.toString());

if

(year % 400 == 0 || (year % 4 == 0

&& year % 100 != 0)) {

//

是闰年

days

= 29;

}

else {

//

不是闰年

days

= 28;

}

}//if

for (int j =

0; j < days; j++) {

cboDay.addItem(""

+ (j + 1));

}//for

}//if

}//if

}//end class

// 事件监听器

class DateItemAdapter implements ItemListener {

private YearMonthDay adaptee;

DateItemAdapter(YearMonthDay adaptee) {

this.adaptee = adaptee;

}

public void itemStateChanged(ItemEvent e)

{

adaptee.cboMonth_itemStateChanged(e);

}

}

测试类：

package com.blue411;

public class TestYearMonthDay {

public static void main(String[] arge){

YearMonthDay testDate = new YearMonthDay();

testDate.setVisible(true);

testDate.setBounds(200, 200, 250, 100);

}

}

测试结果：