Java語言程式設計(第十版基礎篇):printCalendar
阿新 • • 發佈:2019-02-06
注:預設從1800年1月1日星期三開始,要求使用者輸入年份和月份,自動生成對應的日曆。
對應的程式碼如下:
package cn.edu.xyniu;
import java.util.Scanner;
public class PrintCalendar {
public static void main(String[] args) {
//01-1使用者輸入年月並列印
Scanner input = new Scanner(System.in);
System.out.println("Enter year(eg:2018)");
int year = input.nextInt();
System.out.println("Enter month(eg:12)");
int month = input.nextInt();
printMonth(year,month);
}
public static void printMonth(int year,int month) {
printMonthTitle(year,month);
printMonthBody(year,month);
}
public static void printMonthTitle(int year,int month) {
System.out.println(" "+GetMonthName(month)+" "+year);
System.out.println("-----------------------------");
System.out.printf("%4s%4s%4s%4s%4s%4s%4s\n","Sun","Mon","Tus","Wed","Thu","Fri","Sat");
}
//01-2月份轉換
public static String GetMonthName(int m) {
String monthName = "";
switch(m) {
case 1:monthName = "Jannuary";break;
case 2:monthName = "February";break;
case 3:monthName = "March";break;
case 4:monthName = "April";break;
case 5:monthName = "May";break;
case 6:monthName = "June";break;
case 7:monthName = "July";break;
case 8:monthName = "August";break;
case 9:monthName = "September";break;
case 10:monthName = "October";break;
case 11:monthName = "November";break;
case 12:monthName = "December";break;
}
return monthName;
}
/** Print month body */
public static void printMonthBody(int year, int month) {
// Get start day of the week for the first date in the month
int startDay = getStartDay(year, month);
// Get number of days in the month
int numberOfDaysInMonth = getNumberOfDaysInMonth(year, month);
// Pad space before the first day of the month
for (int i = 0; i < startDay; i++)
System.out.print(" ");
for (int i = 1; i <= numberOfDaysInMonth; i++) {
System.out.printf("%4d", i);
if ((i + startDay) % 7 == 0)
System.out.println();
}
System.out.println();
}
/** Get the start day of month/1/year */
public static int getStartDay(int year, int month) {
final int START_DAY_FOR_JAN_1_1800 = 3;
// Get total number of days from 1/1/1800 to month/1/year
int totalNumberOfDays = getTotalNumberOfDays(year, month);
// Return the start day for month/1/year
return (totalNumberOfDays + START_DAY_FOR_JAN_1_1800) % 7;
}
/** Get the total number of days since January 1, 1800 */
public static int getTotalNumberOfDays(int year, int month) {
int total = 0;
// Get the total days from 1800 to year
for (int i = 1800; i < year; i++)//2018 不包含當年2018!
if (isLeapYear(i))
total = total + 366;
else
total = total + 365;
// Add days from Jan to the month prior to the calendar month
for (int i = 1; i < month; i++)//2 不包含2月
total = total + getNumberOfDaysInMonth(year, i);
return total;
}
/** Get the number of days in a month */
public static int getNumberOfDaysInMonth(int year, int month) {
if (month == 1 || month == 3 || month == 5 || month == 7 ||
month == 8 || month == 10 || month == 12)
return 31;
if (month == 4 || month == 6 || month == 9 || month == 11)
return 30;
if (month == 2) return isLeapYear(year) ? 29 : 28;
return 0; // If month is incorrect
}
/** Determine if it is a leap year */
public static boolean isLeapYear(int year) {
return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);
}
}