java打印日歷

簡單的demo

package com.test.transport.service;

import java.text.DateFormatSymbols;
import java.util.Calendar;
import java.util.Locale;

public class DisplayCalendar {
    public static void main(String args[]) {
        Locale.setDefault(Locale.US);
        Calendar calendar = Calendar.getInstance();
        calendar.setLenient(true);
        int today = calendar.get(Calendar.DAY_OF_MONTH);//當天
        int month = calendar.get(Calendar.MONTH);//當月
        int firstDayOfWeek = calendar.getFirstDayOfWeek();//每周從周幾開始
        calendar.set(Calendar.DAY_OF_MONTH, 1);
        int firstday = calendar.get(Calendar.DAY_OF_WEEK);
        String[] weekdayNames = new DateFormatSymbols().getShortWeekdays();
        for(int i=1;i<8;i++){
            System.out.printf("%4s", weekdayNames[i]);
        }
        System.out.println();
        do {
            int day = calendar.get(Calendar.DAY_OF_MONTH);
            if(day == 1){
                System.out.print(" ");
                for(int i =0;i<firstday-1;i++){
                    System.out.print("    ");
                }
            }
            System.out.printf("%3d", day);
            if (day == today) {
                System.out.print("*");
            } else {
                System.out.print(" ");
            }
            calendar.add(Calendar.DAY_OF_MONTH, 1);
            if (calendar.get(Calendar.DAY_OF_WEEK) == firstDayOfWeek) {
                System.out.println();
                System.out.print(" ");
            }
        } while (calendar.get(Calendar.MONTH) == month);
    }
}

輸出結果：