Java Month Day getFirstDayOfMonth(Calendar c)

Description

get First Day Of Month

License

Apache License

Declaration

public static Date getFirstDayOfMonth(Calendar c) 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class Main {
    public static SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");

    public static Date getFirstDayOfMonth(Calendar c) {
        int year = c.get(Calendar.YEAR);
        int month = c.get(Calendar.MONTH);
        int day = 1;
        c.set(year, month, day, 0, 0, 0);
        return c.getTime();
    }/*from  w  w w.  jav a  2 s  .  co  m*/

    public static int get(int field, Date date) {
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        return c.get(field);
    }

    /**
     * Sets the specified field to a date returning a new object.  
     * This does not use a lenient calendar.
     * The original date object is unchanged.
     *
     * @param date  the date, not null
     * @param calendarField  the calendar field to set the amount to
     * @param amount the amount to set
     * @return a new Date object set with the specified value
     * @throws IllegalArgumentException if the date is null
     * @since 2.4
     */
    private static Date set(Date date, int calendarField, int amount) {
        if (date == null) {
            throw new IllegalArgumentException("The date must not be null");
        }
        // getInstance() returns a new object, so this method is thread safe.
        Calendar c = Calendar.getInstance();
        c.setLenient(false);
        c.setTime(date);
        c.set(calendarField, amount);
        return c.getTime();
    }

    public static String getTime(String pattern) {
        return new SimpleDateFormat(pattern).format(new Date());
    }
}

Related

1. getFirstday_Month(Date date, int months)
2. getFirstDayOfCurMonth()
3. getFirstDayOfCurrentMonth()
4. getFirstDayOfLastMonth()
5. getfirstDayOfMonth()
6. getFirstDayOfMonth(Date date)
7. getFirstDayOfMonth(Date date)
8. getFirstDayOfMonth(Date date)
9. getFirstDayOfMonth(Date date)