Java通过矩阵法计算某一天是星期几，矩阵星期几,package com.

Java通过矩阵法计算某一天是星期几，矩阵星期几,package com.

package com.haliluya.java.oj;import java.util.Scanner;public class judgyDay {    private static final int  startYear = 1900;    private static final int[][] dayMap = {     {0,1,2,3,4,5,6},                                                {1,2,3,4,5,6,0},                                                {2,3,4,5,6,0,1},                                                                                                {3,4,5,6,0,1,2},                                                {4,5,6,0,1,2,3},                                                {5,6,0,1,2,3,4},                                                {6,0,1,2,3,4,5}                                            };    public static void main(String[] args) {        Scanner s = new Scanner(System.in);        System.out.println("请输入年");        int year = s.nextInt();        System.out.println("请输入月");        int month = s.nextInt();        System.out.println("请输入号");        int hao = s.nextInt();        System.out.println("输入的年 = "+year);        System.out.println("输入的月 = "+month);        System.out.println("输入的日 = "+hao);        int dayOfWant = 0;        dayOfWant = judgyDayOfAnyYearAnyMonth(year,month,hao);        System.out.println("对应的星期为 （从0算） = "+dayOfWant);    }    /**     * 根据输入的年 月以及号 得到改天的星期数     * @param year     * @param month     * @param hao     * @return     */    private static int judgyDayOfAnyYearAnyMonth(int year, int month, int hao) {        //参数检查              if(year< 1900 ||year >9999 ){            return -1;        }        if(month<0 ||month >12){            return -1;        }        if(hao<0 || hao>31 ){            return -1;        }        //业务开始        //1 算出该月1号距离1900年1月1号多少天        int daysOfLastMonthTotal = gatDaysOfLastMonthTotal(year,month);        //2 的出该月1号是星期几        int firstDay = daysOfLastMonthTotal %7;        System.out.println("给定的月初星期几（从0算）  = "+(firstDay));        //3 算出该号是星期几        int dayJudgyByFirstDay = getDayJudgyByFirstDay(firstDay,hao);        return dayJudgyByFirstDay;    }    private static int getDayJudgyByFirstDay(int firstDay, int hao) {        hao = hao%7;        if(hao ==0){            hao =7;        }        hao -=1;//调整到0下标        System.out.println("取map的第 "+firstDay + "行，第"+ hao +"列");        return dayMap[firstDay][hao];    }    /**     * 算出给定年月的第一天的距离1900的天数     * @param year     * @param month     * @return     */    private static int gatDaysOfLastMonthTotal(int year, int month) {        // 先算年的求和        int totalday = 0;        for(int thisYear = startYear+1 ;thisYear<=year ;thisYear++){            totalday += getTotalDaysByYear(thisYear);        }        //再不上月的求和        for(int i = 1;i <month;i++){            switch(i){            case 1:             case 3:             case 5:             case 7:             case 8:             case 10:             case 12: totalday+= 31;break;            case 2:                 if(isRunYear(year)){                    totalday+= 29;break;                }else                {                    totalday+= 28;break;                }                           case 4:             case 6:             case 9:             case 11:totalday+= 30;break;             }        }        System.out.println("给定年月的第一天距离1900的天数  = "+totalday);        return totalday;    }    /**     * 判断该年有多少天     * @param thisYear     * @return     */    private static int getTotalDaysByYear(int thisYear) {        if((thisYear%4 ==0 && thisYear %100!= 0)||thisYear%400 ==0){            return 366;//二月多一天 29天        }        return 365;    }    private static boolean isRunYear(int thisYear){        return ((thisYear%4 ==0 && thisYear %100!= 0)||thisYear%400 ==0);    }}