Calendar使用 获取星期几、一周日期的函数

1 、获取是星期几

java.util.Date myDate=new java.util.Date();
  Calendar c=Calendar.getInstance();
  c.setTime(myDate);
  int weekDay = c.get(Calendar.DAY_OF_WEEK);
if(Calendar.MONDAY == weekDay){return "星期一";  }
Calendar.TUESDAY ==星期二

Calendar.WEDNESDAY ==星期三
Calendar.THURSDAY ==星期四

Calendar.FRIDAY  ==星期五

Calendar.SATURDAY ==星期六

SUNDAY==星期日
 

 2 获得今天是一周的第几天：

通过在本周的星期一的Calendar上连续加1，获取一周的日期
//（1）获得当前日期与本周一相差的天数
    private int getMondayPlus() {
        Calendar cd = Calendar.getInstance();
        // 获得今天是一周的第几天，星期日是第一天，星期二是第二天......
        int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK);
        if (dayOfWeek == 1) {
            return -6;
        } else {
            return 2 - dayOfWeek;
        }
    }

       //（2） 获得本周星期一的日期
    public Calendar getCurrentMonday() {
        int mondayPlus = this.getMondayPlus();
        GregorianCalendar currentDate = new GregorianCalendar();
        currentDate.add(GregorianCalendar.DATE, mondayPlus);
        Date monday = currentDate.getTime();
        Calendar c = Calendar.getInstance();
        c.setTime(monday);
        return c;
    }

（3）通过在本周的星期一的Calendar上连续加1，获取一周的日期

   public ArrayList<WeekInfo> getCurrentWeekInfoList(){
   Calendar now = Calendar.getInstance();
   todayInfo = now.get(Calendar.YEAR) + "-" + (now.get(Calendar.MONTH) + 1) + "-" + now.get(Calendar.DAY_OF_MONTH);
  
  
   ArrayList<WeekInfo> weekInfoList = new ArrayList<WeekInfo>();
   Calendar mondayDate = getCurrentMonday();                       //本周星期一的Calendar
   String monday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期一";
   WeekInfo weekInfo = new WeekInfo();
   weekInfo.setTodayInfo(todayInfo);
   weekInfo.setWeekDayInfo(monday);
   weekInfo.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo);
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String tuesday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期二";
   WeekInfo weekInfo2 = new WeekInfo();
   weekInfo2.setTodayInfo(todayInfo);
   weekInfo2.setWeekDayInfo(tuesday);
   weekInfo2.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo2);
  
  
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String wednesday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期三";
   WeekInfo weekInfo3 = new WeekInfo();
   weekInfo3.setTodayInfo(todayInfo);
   weekInfo3.setWeekDayInfo(wednesday);
   weekInfo3.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo3);
  
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String thursday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期四";
   WeekInfo weekInfo4 = new WeekInfo();
   weekInfo4.setTodayInfo(todayInfo);
   weekInfo4.setWeekDayInfo(thursday);
   weekInfo4.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo4);
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String friday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期五";
   WeekInfo weekInfo5 = new WeekInfo();
   weekInfo5.setTodayInfo(todayInfo);
   weekInfo5.setWeekDayInfo(friday);
   weekInfo5.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo5);
  
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String saturday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期六";
   WeekInfo weekInfo6 = new WeekInfo();
   weekInfo6.setTodayInfo(todayInfo);
   weekInfo6.setWeekDayInfo(saturday);
   weekInfo6.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo6);
  
   mondayDate.add(Calendar.DAY_OF_MONTH, 1);
   String sunday = (mondayDate.get(Calendar.MONTH) + 1) + "月" + mondayDate.get(Calendar.DAY_OF_MONTH) + "日" + " " + "星期日";
   WeekInfo weekInfo7 = new WeekInfo();
   weekInfo7.setTodayInfo(todayInfo);
   weekInfo7.setWeekDayInfo(sunday);
   weekInfo7.setWeekDate(mondayDate.get(Calendar.YEAR) + "-" + (mondayDate.get(Calendar.MONTH) + 1) + "-" + mondayDate.get(Calendar.DAY_OF_MONTH));
   weekInfoList.add(weekInfo7);
  
   return weekInfoList;
}