能不能告诉我哪里错了

Question

import java.util.*;public class Example3223 { public static void main(String[] args) throws Exception{ Scanner S1=new Scanner(System.in); System.out.println("请输入你想知道月历的年数（格式：yyyy）："); int year=S1.nextInt(); if(year<1){ System.out.println("输入的年份不能小于1！"); return; } System.out.println("请输入你想知道月历的月数（格式：mm）："); int month=S1.nextInt(); if(month<1||month>12){ System.out.println("输入的月份不能小于1和大于12！"); return; } System.out.println("这是"+year+"年"+month+"月的月历："); System.out.println("***********************************************************"); System.out.println("日\t一\t二\t三\t四\t五\t六"); Example3223 y=new Example3223(); y.print(year,month); } public int getWeek(int year,int month){ Date date=new Date(); date.setYear(year); date.setMonth(month); Calendar calendar=Calendar.getInstance(); calendar.setTime(date); return calendar.get(calendar.DAY_OF_WEEK); } public void print(int year,int month){ int day=getDay(year,month); int week=getWeek(year,month); for(int i=0;i<=week;i++){ System.out.print(" \t"); } for(int j=1;j<=day;j++){ if((j+week)%7==0){ System.out.println(); } System.out.print(j+"\t"); } } public int getDay(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: if(isLeapYear(year))return 29; else return 28; } return 0; } public static boolean isLeapYear(int y){ return((y%4==0&&y%100!=0)||y%400==0); }}

Answer 1

main方法里面不需要return，实在要跳出方法可以采用System.exit(1）；