Java Day of Week getWeekDay(Date date)

Description

Return week day of specified date

License

Open Source License

Parameter

Parameter	Description
date	specified date

Return

week day of @param date

Declaration

public static int getWeekDay(Date date) 

Method Source Code

//package com.java2s;
/*// w w w .ja  v  a  2 s. co  m
 * File: $RCSfile$
 *
 * Copyright (c) 2005 Wincor Nixdorf International GmbH,
 * Heinz-Nixdorf-Ring 1, 33106 Paderborn, Germany
 * All Rights Reserved.
 *
 * This software is the confidential and proprietary information
 * of Wincor Nixdorf ("Confidential Information"). You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered
 * into with Wincor Nixdorf.
 */

import java.util.Date;
import java.util.Calendar;
import java.util.List;
import java.util.ArrayList;

public class Main {
    /**
     * Return week day of specified date
     *
     * @param date specified date
     * @return week day of @param date
     */
    public static int getWeekDay(Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        return c.get(Calendar.DAY_OF_WEEK);
    }

    /**
     * Return dates list with specified week day between specified begin data and end date
     *
     * @param weekDay   week day for exampke, Mon, Tus.....
     * @param beginDate begin date
     * @param endDate   end date
     * @return array includes expected date objects whose week day equals to @param weekDay
     */
    public static List getWeekDay(int weekDay, Date beginDate, Date endDate) {
        int startMonth = getDateMonth(beginDate).intValue();
        int startYear = getDateYear(beginDate).intValue();
        Date startDateMonthFirstDate = getFirstDayOfMonth(startYear, startMonth - 1);
        int firstDayOfStartDate = getWeekDay(startDateMonthFirstDate) - 1;
        int offset = weekDay - firstDayOfStartDate;
        if (offset < 0) {
            offset += 7;
        }
        Date weekStartDate = add(startDateMonthFirstDate, offset, Calendar.DAY_OF_YEAR);
        List lstResult = new ArrayList();
        while (compareYMD(weekStartDate, endDate)) {
            lstResult.add(weekStartDate);
            weekStartDate = add(weekStartDate, 7, Calendar.DAY_OF_YEAR);
        }
        return lstResult;
    }

    /**
     * Return month of specified date
     *
     * @param date specified date
     * @return month value
     */
    public static Integer getDateMonth(Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        return new Integer(c.get(Calendar.MONTH) + 1);
    }

    /**
     * Return year of specified date
     *
     * @param date specified date
     * @return year  value
     */
    public static Integer getDateYear(Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        return new Integer(c.get(Calendar.YEAR));
    }

    /**
     * Return first day of date with specified year and month
     *
     * @param year  specified year
     * @param month specified month
     * @return first day value of year of current date
     */
    public static Date getFirstDayOfMonth(int year, int month) {
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);
        cal.set(Calendar.MONTH, month);
        cal.set(Calendar.DAY_OF_MONTH, 1);
        return cal.getTime();
    }

    /**
     * Add Interval to Date
     *
     * @param inputDate    Date to Add
     * @param interval     Interval to added. Subtract is interval is nagative
     * @param calendarUnit Calendar.Year/Calendar.Month/Calendar.Day/Calendar.Hour/Calendar.MInute
     * @return Date added
     */
    public static Date add(Date inputDate, int interval, int calendarUnit) {
        Calendar cal = Calendar.getInstance();
        cal.setTime(formateDateWithoutTime(inputDate));
        cal.add(calendarUnit, interval);
        return cal.getTime();
    }

    /**
     * add by xie compare date only compare year month day
     *
     * @param begindate begin date
     * @param enddate   end date
     * @return begindate > endate as false
     */
    public static boolean compareYMD(Date begindate, Date enddate) {
        boolean isBefore = true;
        Calendar startCalendar = Calendar.getInstance();
        startCalendar.setTime(begindate);
        Calendar endCalendar = Calendar.getInstance();
        endCalendar.setTime(enddate);
        int startYear = startCalendar.get(Calendar.YEAR);
        int startMonth = startCalendar.get(Calendar.MONTH);
        int startDay = startCalendar.get(Calendar.DAY_OF_MONTH);
        int endYear = endCalendar.get(Calendar.YEAR);
        int endMonth = endCalendar.get(Calendar.MONTH);
        int endDay = endCalendar.get(Calendar.DAY_OF_MONTH);
        if (startYear > endYear) {
            isBefore = false;
        } else if (startYear == endYear) {
            if (startMonth > endMonth) {
                isBefore = false;
            } else if (startMonth == endMonth) {
                if (startDay > endDay) {
                    isBefore = false;
                }
            }
        }
        return isBefore;
    }

    /**
     * Format Date to make it''s hour/minute/second to 0
     *
     * @param inputDate Date to Format
     * @return Date with Year/Month/Day is same with input one while hour/minute/second is 0
     */
    public static Date formateDateWithoutTime(Date inputDate) {
        Date outputDate = inputDate;
        Calendar cal = Calendar.getInstance();
        cal.setTime(outputDate);
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.SECOND, 0);
        outputDate = cal.getTime();
        return outputDate;
    }
}

Related

1. getWeekday(Date d)
2. getWeekDay(Date d)
3. getWeekDay(Date date)
4. getWeekDay(Date date)
5. getWeekDay(Date date)
6. getWeekDay(Date dt, int weekDay)
7. getWeekDay(String strDate)
8. getWeekdayDate(Date actualDate)
9. getWeekdayInterval(Date date)