3.9mydate.java

JAVA程序设计的源代码

import javax.swing.JOptionPane;
public class MyDate{
private int year;    
private int month;    
private int day;  

public MyDate(int month,int day,int year){   
if  (month>0 && month<=12){    //判断参数month是否有效
this.month=month;   
}
else{
month=1;    //月份无效置1
}
this.year=year;   
this.day=checkDay(day);    //判断day是否有效
}
private int checkDay(int testDay)  {
int daysPerMonth[]={0,31,28,31,30,31,30,31,31,30,31,30,31};
if (testDay>0 && testDay<=daysPerMonth[month]){    //判断天数是否有效
return testDay;   
}

if(month==2 && testDay == 29 && (year%400==0 || (year%4==0 && year%100 !=0))){    //判断闰年的情况
return testDay;   
}
return 1;    //天数无效置1
}

public String tostring()  {
return month+"/"+day+"/"+year;   //以字符串的形式返回date
}

public static void main(String []args)  {
MyDate date1=new MyDate(7,31,2004);
MyDate date2=new MyDate(2,29,2004);
MyDate date3=new MyDate(13,3,2003);

JOptionPane.showMessageDialog(null,date1.tostring()+"\n"+
date2.tostring()+"\n"+date3.tostring(),"Date Test Demo",
JOptionPane.INFORMATION_MESSAGE);    ////输出显示日期信息
System.exit(0);   
}
}