编写一个程序，输出一个月的日历。

方法一：

import java.util.Calendar;

import java.util.Scanner;

public class YueLi {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int a = sc.nextInt();//a表示你将要输入几个年月

sc.nextLine();

Calendar calendar = Calendar.getInstance();

for(int i = 0; i < a; i++){

String s = sc.nextLine();

String[] strs = s.split("-");

int year = Integer.parseInt(strs[0]);

int month = Integer.parseInt(strs[1]);

calendar.set(Calendar.YEAR, year); //设置年

calendar.set(Calendar.MONTH, month-1);

calendar.set(Calendar.DATE, 1);

//System.out.println(calendar.get(7));

for(int j =1; j < calendar.get(Calendar.DAY_OF_WEEK); j++) {

System.out.print(" ");//输出开始前面的空格

}

for(int k = 1; k <= whichMonth(year, month); k++) {

calendar.set(Calendar.DATE, k);

if(calendar.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY)

System.out.println();

if(k <= 10) { //为了输出对齐

System.out.print(k+" ");

} else {

System.out.print(k+ " ");

}

}

}

}

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

int days = 0;

switch (month){

case 1:

case 3:

case 5:

case 7:

case 8:

case 10:

case 12:

days = 31;

break;

case 4:

case 6:

case 9:

case 11:

days = 30;

break;

case 2:

if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0)) {//润年

days = 29;

} else {

days = 28;

}

break;

}

return days;

}

}

方法二：

import java.util.Scanner;

public class DisplayYueLi{

public static void main(String[] args){

Scanner sc=new Scanner(System.in);

String input1=sc.nextLine();

String[] input2=input1.split("-");

int year=Integer.parseInt(input2[0]);

int month=Integer.parseInt(input2[1]);

int fristDay=GetfristDay(year,month);//

int mDay=GetmDay(year,month);

DisplayYueLi(fristDay,mDay);

}

static int GetfristDay(int year,int month){

int zDays=0;

for(int i=1;i<year;i++){

if(i%4==0&&i%100!=0||i%400==0){

zDays=zDays+366;

}

else{

zDays=zDays+365;

}

}

for(int j=1;j<month;j++){

switch(j){

case 1:

case 3:

case 5:

case 7:

case 8:

case 10:

case 12:

zDays=zDays+31;

break;

case 4:

case 6:

case 9:

case 11:

zDays=zDays+30;

break;

case 2:

if(year%4==0&&year%100!=0||year%400==0){

zDays=zDays+29;

}

else{

zDays=zDays+28;

}

}

}

int fristDay=(int)(zDays+1)%7;

// System.out.println("fristDay=" +fristDay);

return(fristDay);

}

static int GetmDay(int year,int month){

int mDay=0;

switch(month){

case 1:

case 3:

case 5:

case 7:

case 8:

case 10:

case 12:

mDay=31;

break;

case 4:

case 6:

case 9:

case 11:

mDay=30;

break;

case 2:

if(year%4==0&&year%100!=0||year%400==0){

mDay=29;

}

else{

mDay=28;

}break;

}

return(mDay);

}

static void DisplayYueLi(int fristDay,int mDay){

String space=" ";

System.out.println(space+"日"+space+"一"+space+"二"+space+"三"+space+"四"+space+"五"+space+"六");

for(int m=0;m<fristDay;m++){

System.out.print(space+" ");

}

for(int n=1;n<=mDay;n++){

if((n+fristDay)%7==0&&n!=1){

if (n<10)

System.out.println(space+" "+n);

else

System.out.println(space+n);

}

else{

if (n<10)

System.out.print(space+" "+n);

else

System.out.print(space+n);

}

}

}

}