本文实例讲述了Java实现按年月打印日历功能。分享给大家供大家参考，具体如下：

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

public class CalendarBook {

public static void main(String[] args) throws ParseException {

CalendarBook cb = new CalendarBook();

cb.printWeekTitle();

cb.printCalendar(2018, 3);

}

public void printCalendar(int year, int month) throws ParseException {

String monthStr; // 格式化月份，因为要转成yyyyMMdd格式的

if (month < 10) {

monthStr = "0" + month;

} else {

monthStr = month + ""; // 数字跟字符串拼接转成字符串格式

}

String yearMonthStr = year + monthStr;

SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");

Calendar calendarEnd = Calendar.getInstance();

Calendar calendarStart = Calendar.getInstance();

// 根据年份和月份得到输入月份有多少天

int monthDays = getMonthLastDay(year, month);

// 月初的date字符串

String dateStartStr = yearMonthStr + "01";

// 月末的date字符串

String dateEndStr = yearMonthStr + monthDays;

Date startDate = sdf.parse(dateStartStr);

Date endDate = sdf.parse(dateEndStr);

calendarStart.setTime(startDate);

calendarEnd.setTime(endDate);

// 得到输入月份有多少周

int weeks = calendarEnd.get(Calendar.WEEK_OF_MONTH);

// 得到当月第一天是星期几，这里周日为第一天，从1开始，周一则为2

int dayOfWeek = calendarStart.get(Calendar.DAY_OF_WEEK);

int day = 1;

// 当月的第一周做特殊处理，单独打印一行

for (int i = 1; i <= 7; i++) {

if (i >= dayOfWeek) {

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

day++;

} else {

System.out.print(" ");

}

}

System.out.println();

// 开始打印从第二周开始的日期

for (int week = 1; week < weeks; week++) {

for (int i = 1; i <= 7; i++) {

if (day > monthDays) {

break;

}

if (day < 10) {

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

} else {

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

}

day++;

}

System.out.println();

}

}

public int getMonthLastDay(int year, int month) {

int monthDay;

int[][] day = { { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },

{ 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 } };

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

// 闰年

monthDay = day[1][month];

} else {

monthDay = day[0][month];

}

return monthDay;

}

public void printWeekTitle() {

System.out.println("日" + " " + "一" + " " + "二" + " " + "三"

+ " " + "四" + " " + "五" + " " + "六");

}

}

运行结果截图(运行效果，字体大小5号最佳)：

PS：这里再为大家推荐几款关于日期与时间计算的在线工具供大家参考使用：

希望本文所述对大家java程序设计有所帮助。