Checks if two date objects are on the same day ignoring time : Date Calculation « Data Type « Java Tutorial






import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Calendar;
import java.util.Date;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */




/**
 * A suite of utilities surrounding the use of the
 * {@link java.util.Calendar} and {@link java.util.Date} object.
 * 
 * DateUtils contains a lot of common methods considering manipulations
 * of Dates or Calendars. Some methods require some extra explanation.
 * The truncate and round methods could be considered the Math.floor(),
 * Math.ceil() or Math.round versions for dates
 * This way date-fields will be ignored in bottom-up order.
 * As a complement to these methods we've introduced some fragment-methods.
 * With these methods the Date-fields will be ignored in top-down order.
 * Since a date without a year is not a valid date, you have to decide in what
 * kind of date-field you want your result, for instance milliseconds or days.
 * 
 *   
 *   
 *
 * @author <a href="mailto:sergek@lokitech.com">Serge Knystautas</a>
 * @author Stephen Colebourne
 * @author Janek Bogucki
 * @author <a href="mailto:ggregory@seagullsw.com">Gary Gregory</a>
 * @author Phil Steitz
 * @author Robert Scholte
 * @since 2.0
 * @version $Id: DateUtils.java 634096 2008-03-06 00:58:11Z niallp $
 */
public class Main {

  //-----------------------------------------------------------------------
  /**
   * Checks if two date objects are on the same day ignoring time.
   *
   * 28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true.
   * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.
   * 
   * 
   * @param date1  the first date, not altered, not null
   * @param date2  the second date, not altered, not null
   * @return true if they represent the same day
   * @throws IllegalArgumentException if either date is <code>null</code>
   * @since 2.1
   */
  public static boolean isSameDay(Date date1, Date date2) {
      if (date1 == null || date2 == null) {
          throw new IllegalArgumentException("The date must not be null");
      }
      Calendar cal1 = Calendar.getInstance();
      cal1.setTime(date1);
      Calendar cal2 = Calendar.getInstance();
      cal2.setTime(date2);
      return isSameDay(cal1, cal2);
  }

  /**
   * Checks if two calendar objects are on the same day ignoring time.
   *
   * 28 Mar 2002 13:45 and 28 Mar 2002 06:01 would return true.
   * 28 Mar 2002 13:45 and 12 Mar 2002 13:45 would return false.
   * 
   * 
   * @param cal1  the first calendar, not altered, not null
   * @param cal2  the second calendar, not altered, not null
   * @return true if they represent the same day
   * @throws IllegalArgumentException if either calendar is <code>null</code>
   * @since 2.1
   */
  public static boolean isSameDay(Calendar cal1, Calendar cal2) {
      if (cal1 == null || cal2 == null) {
          throw new IllegalArgumentException("The date must not be null");
      }
      return (cal1.get(Calendar.ERA) == cal2.get(Calendar.ERA) &&
              cal1.get(Calendar.YEAR) == cal2.get(Calendar.YEAR) &&
              cal1.get(Calendar.DAY_OF_YEAR) == cal2.get(Calendar.DAY_OF_YEAR));
  }
}








2.42.Date Calculation
2.42.1.Compare date time using after method of Java Calendar
2.42.2.Compare date time using before method of Java Calendar
2.42.3.Increment and Decrement a Date Using the Calendar Class
2.42.4.Increment and Decrement Months Using the Calendar Class
2.42.5.Add or substract days to current date using Java Calendar
2.42.6.Substract days from current date using Calendar.add method
2.42.7.Add hours to current date using Calendar.add method
2.42.8.Calendar adjust date automatically
2.42.9.Substract hours from current date using Calendar.add method
2.42.10.Add minutes to current date using Calendar.add method
2.42.11.Substract minutes from current date using Calendar.add method
2.42.12.Add months to current date using Calendar.add method
2.42.13.Substract months from current date using Calendar.add method
2.42.14.Add seconds to current date using Calendar.add method
2.42.15.Substract seconds from current time using Calendar.add method
2.42.16.Add week to current date using Calendar.add method
2.42.17.Substract week from current date
2.42.18.Add year to current date using Calendar.add method
2.42.19.Substract year from current date
2.42.20.Substract 30 days from the calendar
2.42.21.Add 10 months to the calendar
2.42.22.Substract 1 year from the calendar
2.42.23.If a date is after another date
2.42.24.If a date is before another date
2.42.25.Compute days between 2 dates
2.42.26.Calculate the age
2.42.27.Determining If a Year Is a Leap Year
2.42.28.Determining the Day-of-Week for a Particular Date
2.42.29.Add hours, minutes or seconds to a date
2.42.30.Find the Difference Between Two Given Dates
2.42.31.add another 12 hours and print out the date and time
2.42.32.subtract 4 hours from the time and print out the date and time
2.42.33.add 8 days to the current date and print out the date and time
2.42.34.Returns the number of days within the fragment.
2.42.35.Returns the number of hours within the fragment.
2.42.36.Returns the number of milliseconds within the fragment.
2.42.37.Returns the number of minutes within the fragment.
2.42.38.Returns the number of seconds within the fragment.
2.42.39.Returns a Date set just to Noon, to the closest possible millisecond of the day.
2.42.40.Returns a Date set to the last possible millisecond of the month, just before midnight.
2.42.41.Returns a Date set to the first possible millisecond of the month, just after midnight.
2.42.42.Returns a Date set to the last possible millisecond of the minute.
2.42.43.Returns a Date set to the last possible millisecond of the day, just before midnight.
2.42.44.Returns a Date set to the first possible millisecond of the day, just after midnight.
2.42.45.Returns true if endDate is after startDate or if startDate equals endDate.
2.42.46.Round this date, leaving the field specified as the most significant field.
2.42.47.Checks if two date objects represent the same instant in time
2.42.48.Checks if two calendar objects represent the same local time.
2.42.49.Checks if two date objects are on the same day ignoring time
2.42.50.Truncate this date(Calendar), leaving the field specified as the most significant field.
2.42.51.Truncate this date, leaving the field specified as the most significant field.
2.42.52.Days Till End Of Year
2.42.53.Convert day of year to day of month
2.42.54.Determine if an hour is between an interval