Java tutorial
/******************************************************************************* * Gisgraphy Project * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA * * Copyright 2008 Gisgraphy project * David Masclet <davidmasclet@gisgraphy.com> * * *******************************************************************************/ package com.gisgraphy.util; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.Locale; import java.util.MissingResourceException; import java.util.ResourceBundle; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.context.i18n.LocaleContextHolder; import com.gisgraphy.domain.valueobject.Constants; /** * Date Utility Class used to convert Strings to Dates and Timestamps * * @author <a href="mailto:matt@raibledesigns.com">Matt Raible</a> Modified by * <a href="mailto:dan@getrolling.com">Dan Kibler </a> to correct time * pattern. Minutes should be mm not MM (MM is month). */ public class DateUtil { private static Log log = LogFactory.getLog(DateUtil.class); private static final String TIME_PATTERN = "HH:mm"; /** * Checkstyle rule: utility classes should not have public constructor */ private DateUtil() { } /** * Return default datePattern (MM/dd/yyyy) * * @return a string representing the date pattern on the UI */ public static String getDatePattern() { Locale locale = LocaleContextHolder.getLocale(); String defaultDatePattern; try { defaultDatePattern = ResourceBundle.getBundle(Constants.BUNDLE_KEY, locale).getString("date.format"); } catch (MissingResourceException mse) { defaultDatePattern = "MM/dd/yyyy"; } return defaultDatePattern; } public static String getDateTimePattern() { return DateUtil.getDatePattern() + " HH:mm:ss.S"; } /** * This method attempts to convert an Oracle-formatted date in the form * dd-MMM-yyyy to mm/dd/yyyy. * * @param aDate * date from database as a string * @return formatted string for the ui */ public static String getDate(Date aDate) { SimpleDateFormat df; String returnValue = ""; if (aDate != null) { df = new SimpleDateFormat(getDatePattern()); returnValue = df.format(aDate); } return (returnValue); } /** * This method generates a string representation of a date/time in the * format you specify on input * * @param aMask * the date pattern the string is in * @param strDate * a string representation of a date * @return a converted Date object * @see java.text.SimpleDateFormat * @throws ParseException * when String doesn't match the expected format */ public static Date convertStringToDate(String aMask, String strDate) throws ParseException { SimpleDateFormat df; Date date; df = new SimpleDateFormat(aMask); if (log.isDebugEnabled()) { log.debug("converting '" + strDate + "' to date with mask '" + aMask + "'"); } try { date = df.parse(strDate); } catch (ParseException pe) { // log.error("ParseException: " + pe); throw new ParseException(pe.getMessage(), pe.getErrorOffset()); } return (date); } /** * This method returns the current date time in the format: MM/dd/yyyy HH:MM * a * * @param theTime * the current time * @return the current date/time */ public static String getTimeNow(Date theTime) { return getDateTime(TIME_PATTERN, theTime); } /** * This method returns the current date in the format: MM/dd/yyyy * * @return the current date * @throws ParseException * when String doesn't match the expected format */ public static Calendar getToday() throws ParseException { Date today = new Date(); SimpleDateFormat df = new SimpleDateFormat(getDatePattern()); // This seems like quite a hack (date -> string -> date), // but it works ;-) String todayAsString = df.format(today); Calendar cal = new GregorianCalendar(); cal.setTime(convertStringToDate(todayAsString)); return cal; } /** * This method generates a string representation of a date's date/time in * the format you specify on input * * @param aMask * the date pattern the string is in * @param aDate * a date object * @return a formatted string representation of the date * @see java.text.SimpleDateFormat */ public static String getDateTime(String aMask, Date aDate) { SimpleDateFormat df = null; String returnValue = ""; if (aDate == null) { log.error("aDate is null!"); } else { df = new SimpleDateFormat(aMask); returnValue = df.format(aDate); } return (returnValue); } /** * This method generates a string representation of a date based on the * System Property 'dateFormat' in the format you specify on input * * @param aDate * A date to convert * @return a string representation of the date */ public static String convertDateToString(Date aDate) { return getDateTime(getDatePattern(), aDate); } /** * This method converts a String to a date using the datePattern * * @param strDate * the date to convert (in format MM/dd/yyyy) * @return a date object * @throws ParseException * when String doesn't match the expected format */ public static Date convertStringToDate(String strDate) throws ParseException { Date aDate = null; try { if (log.isDebugEnabled()) { log.debug("converting date with pattern: " + getDatePattern()); } aDate = convertStringToDate(getDatePattern(), strDate); } catch (ParseException pe) { log.error("Could not convert '" + strDate + "' to a date, throwing exception"); throw new ParseException(pe.getMessage(), pe.getErrorOffset()); } return aDate; } }