MyDate

package MyDate;

public class MyDate{

private int year,month,day;

private static int thisYear;
static { thisYear=2012; }

public MyDate(int year,int month,int day) {

this.set(year,month,day); }

public MyDate() { this(1970,1,1); }

public MyDate(MyDate d) { this.set(d); }

public void set(int year,int month,int day) {

this.year=year; this.month=(month>=1&&month<=12)?month:1; this.day=(day>=1&&day<=31)?day:1; }

public void set(MyDate d) { set(d.year,d.month,d.day); }

public int getYear() { return this.year; }

public int getMonth() {return this.month;}

public int getDay()  {return this.day;}

public String toString() {

return year+"年"+String.format("%02d",month)+"月"+String.format("%02d",day)+"日"; }

public static int getThisYear() { return thisYear; }

public static boolean isLeapYear(int year) {

return year%400==0||year%100!=0&&year%4==0; }

public boolean isLeapYear()   {    return isLeapYear(this.year);   }

public boolean equals(MyDate d) { return this==d||d!=null&&this.day==d.year&&this.month==d.month&&this.day==d.day; }

public static int daysOfMonth(int year,int month) {  

switch(month)   {   case 1:case 3:case 5:case 7:case 8:case 10:case 12: return 31;   case 4:case 6:case 9:case 11: return 30;   case 2: return MyDate.isLeapYear(year)?29:28;   default: return 0;   }

}

public int daysOfMonth() { return daysOfMonth(this.year,this.month); }

public void tomorrow() { this.day++; if(this.day>this.daysOfMonth())

{ this.day=1; this.month++; if(this.month>12) { this.month=1; this.year++; } }

}

public MyDate yestoday() { MyDate date=new MyDate(this); date.day--; if(date.day==0)

{ date.month--; if(date.month==0) { date.month=12; date.year--; } date.day=daysOfMonth(date.year,date.month); } return date; }

}

class MyDate_ex { public static void main(String args[])

{ System.out.println("今年是"+MyDate.getThisYear()+",闰年?"+MyDate.isLeapYear(MyDate.getThisYear())); MyDate d1=new MyDate(2012,12,31); MyDate d2=new MyDate(d1); System.out.println("d1:"+d1+",d2"+",d1==d2?"+(d1==d2)+",d1.equal(d2)?"+d1.equals(d2)); System.out.print(d1+"的明天是 "); d1.tomorrow(); System.out.println(d1+" "+d1+"的昨天是 "+(d2=d1.yestoday())); }

}