Java------日历程序

首先构造了一个日历对象：

LocalDate date = LocalDate.now();

用当前的日期进行初始化：

int month = date.getMonthValue();
int today = date.getDayOfMonth();

然后， 将date设置为本月第一天，并得到这一天为星期几：

date = date.minusDays(today - 1);

变量weekday设置为DayOfWeek 类型对象， 调用getValue 方法来得到星期几的一个数值：

DayOfWeek weekday = date.getDayOfWeek();
int value = weekday.getValue();

日历的第一行是缩进的， 使得约饭的第一天指向相应的星期几：

System.out.println("Mon Tue Wed Thu Fri Sat Sun");
for(int i = 1; i < value; ++i) 
            System.out.println("    ");

打印日历主体， date白努力一个月中的每一天， 当前日期用* 标记， 如果到新的一周则换行。

while(date.getMonthValue() == month) {
			System.out.printf("%3d", date.getDayOfMonth());
			if(date.getDayOfMonth() == today)
				System.out.print("*");
			else
				System.out.print(" ");
			date = date.plusDays(1);
			if(date.getDayOfWeek().getValue() == 1)
				System.out.println();
		}

完整程序： 

import java.time.*;

public class CalendarTest {
	public static void main(String[] args) {
		LocalDate date = LocalDate.now();
		int month = date.getMonthValue();
		int today = date.getDayOfMonth();
		
		date = date.minusDays(today - 1);
		DayOfWeek weekday = date.getDayOfWeek();
		int value = weekday.getValue();
		
		System.out.println("Mon Tue Wed Thu Fri Sat Sun");
		for(int i = 1; i < value; ++i) {
			System.out.println("    ");
		}
		while(date.getMonthValue() == month) {
			System.out.printf("%3d", date.getDayOfMonth());
			if(date.getDayOfMonth() == today)
				System.out.print("*");
			else
				System.out.print(" ");
			date = date.plusDays(1);
			if(date.getDayOfWeek().getValue() == 1)
				System.out.println();
		}
		if(date.getDayOfWeek().getValue() != 1)
			System.out.println();
	}	
}