Java Week Day getFirstDayOfWeek(Date date)

Description

get First Day Of Week

License

Apache License

Declaration

public static Date getFirstDayOfWeek(Date date) 

Method Source Code

//package com.java2s;
/*//from  ww  w .j  av a 2  s .co m
 *    Copyright (c) 2015 Power Group.
 *     Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 *
 */

import java.util.*;

public class Main {

    public static Date getFirstDayOfWeek(Date date) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        return getADayOfWeek(calendar, Calendar.MONDAY).getTime();
    }

    private static Calendar getADayOfWeek(Calendar day, int dayOfWeek) {
        int week = day.get(Calendar.DAY_OF_WEEK);
        if (week == dayOfWeek) {
            return day;
        }
        int diffDay = dayOfWeek - week;
        if (week == Calendar.SUNDAY) {
            diffDay -= 7;
        } else if (dayOfWeek == Calendar.SUNDAY) {
            diffDay += 7;
        }
        day.add(Calendar.DATE, diffDay);
        return day;
    }
}

Related

1. getENWeekDay()
2. getFirstday_Lastday_Week()
3. getFirstDayOfLastWeek(Date date)
4. getFirstDayOfWeek()
5. getFirstDayOfWeek()
6. getFirstDayOfWeek(Date date)
7. getFirstDayOfWeek(final Date date)
8. getFirstDayOfWeek(String format)
9. getFirstDayOfWeek(String str, int week)