Java编程Gauss消元和判断闰年

import java.io.*; import java.util.*; class Date{ int year; int month; int day; public Date(){ Calendar cal=Calendar.getInstance(); year=cal.get(Calendar.YEAR); month=cal.get(Calendar.MONTH); day=cal.get(Calendar.DATE); } public void LeapYear(int year){ this.year=year; if((this.year%4==0&&this.year%100!=0)||this.year%400==0) System.out.println(this.year+"年是闰年"); else System.out.println(this.year+"年不是闰年"); } public void Day(){ Calendar cal=Calendar.getInstance(); year=cal.get(Calendar.YEAR); month=cal.get(Calendar.MONTH); day=cal.get(Calendar.DATE); System.out.println("今天的日期是:"+year+"年"+month+"月"+day+"天"); } public void nextDay(){ int newDay = day + 1; int newMonth =month; int newYear = year; if(newDay > 30){ newMonth ++; newDay = 1; } if(newMonth > 12){ newYear ++; newMonth = 1; } System.out.println("明天的日期是:"+newYear+"年"+newMonth+"月"+newDay+"日"); } } public class TestDate{ public static void main(String args[]) throws IOException { BufferedReader br= new BufferedReader(new InputStreamReader(System.in)); System.out.print("请输入年份:"); String num=br.readLine(); int year=Integer.parseInt(num); Date rn=new Date();rn.LeapYear(year); Date today=new Date();today.Day(); Date tomorrow=new Date();tomorrow.nextDay(); } }