content: /*
   * This library is part of OpenCms -
   * the Open Source Content Management System
   *
   * Copyright (c) Alkacon Software GmbH & Co. KG (https://www.alkacon.com)
   *
   * 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.
   *
   * For further information about Alkacon Software GmbH & Co. KG, please see the
   * company website: https://www.alkacon.com
   *
   * For further information about OpenCms, please see the
   * project website: https://www.opencms.org
   *
   * 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
   */
  
  package org.opencms.util;
  
  import org.opencms.i18n.CmsLocaleManager;
  
  import java.text.DateFormat;
  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.TimeZone;
  
  /**
   *
   * Utilities to get and set formated dates in OpenCms.<p>
   *
   * @since 6.0.0
   */
  public final class CmsDateUtil {
  
      /** The "GMT" time zone, used when formatting http headers. */
      protected static final TimeZone GMT_TIMEZONE = TimeZone.getTimeZone("GMT");
  
      /** The default format to use when formatting http headers. */
      protected static final DateFormat HEADER_DEFAULT = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.US);
  
      /** The default format to use when formatting old cookies. */
      protected static final DateFormat OLD_COOKIE = new SimpleDateFormat("EEE, dd-MMM-yyyy HH:mm:ss z", Locale.US);
  
      /**
       * Hides the public constructor.<p>
       */
      private CmsDateUtil() {
  
          // noop
      }
  
      /**
       * Returns a formated date String from a Date value,
       * the formatting based on the provided options.<p>
       *
       * @param date the Date object to format as String
       * @param format the format to use, see {@link DateFormat} for possible values
       * @param locale the locale to use
       * @return the formatted date
       */
      public static String getDate(Date date, int format, Locale locale) {
  
          DateFormat df = DateFormat.getDateInstance(format, locale);
          return df.format(date);
      }
  
      /**
       * Returns a formated date String form a timestamp value,
       * the formatting based on the OpenCms system default locale
       * and the {@link DateFormat#SHORT} date format.<p>
       *
       * @param time the time value to format as date
       * @return the formatted date
       */
      public static String getDateShort(long time) {
  
          return getDate(new Date(time), DateFormat.SHORT, CmsLocaleManager.getDefaultLocale());
      }
  
      /**
       * Returns a formated date and time String from a Date value,
       * the formatting based on the provided options.<p>
       *
       * @param date the Date object to format as String
       * @param format the format to use, see {@link DateFormat} for possible values
       * @param locale the locale to use
       * @return the formatted date
       */
      public static String getDateTime(Date date, int format, Locale locale) {
  
          DateFormat df = DateFormat.getDateInstance(format, locale);
          DateFormat tf = DateFormat.getTimeInstance(format, locale);
          StringBuffer buf = new StringBuffer();
          buf.append(df.format(date));
          buf.append(" ");
          buf.append(tf.format(date));
          return buf.toString();
      }
  
      /**
       * Returns a formated date and time String form a timestamp value,
       * the formatting based on the OpenCms system default locale
       * and the {@link DateFormat#SHORT} date format.<p>
       *
       * @param time the time value to format as date
       * @return the formatted date
       */
      public static String getDateTimeShort(long time) {
  
          return getDateTime(new Date(time), DateFormat.SHORT, CmsLocaleManager.getDefaultLocale());
      }
  
      /**
       * Returns the number of days passed since a specific date.<p>
       *
       * @param dateLastModified the date to compute the passed days from
       *
       * @return the number of days passed since a specific date
       */
      public static int getDaysPassedSince(Date dateLastModified) {
  
          GregorianCalendar now = new GregorianCalendar();
          GregorianCalendar lastModified = (GregorianCalendar)now.clone();
          lastModified.setTimeInMillis(dateLastModified.getTime());
          return (now.get(Calendar.DAY_OF_YEAR) - lastModified.get(Calendar.DAY_OF_YEAR))
              + ((now.get(Calendar.YEAR) - lastModified.get(Calendar.YEAR)) * 365);
      }
  
      /**
       * Returns a formated date and time String form a timestamp value based on the
       * HTTP-Header date format.<p>
       *
       * @param time the time value to format as date
       * @return the formatted date
       */
      synchronized public static String getHeaderDate(long time) {
  
          if (HEADER_DEFAULT.getTimeZone() != GMT_TIMEZONE) {
              // ensure GMT is used as time zone for the header generation
              HEADER_DEFAULT.setTimeZone(GMT_TIMEZONE);
          }
  
          return HEADER_DEFAULT.format(new Date(time));
      }
  
      /**
       * Returns a formatted date and time String form a timestamp value based on the
       * (old) Netscape cookie date format.<p>
       *
       * @param time the time value to format as date
       * @return the formatted date
       */
      synchronized public static String getOldCookieDate(long time) {
  
          if (OLD_COOKIE.getTimeZone() != GMT_TIMEZONE) {
              // ensure GMT is used as time zone for the header generation
              OLD_COOKIE.setTimeZone(GMT_TIMEZONE);
          }
  
          try {
              return OLD_COOKIE.format(new Date(time));
          } catch (Throwable t) {
              return OLD_COOKIE.format(new Date());
          }
      }
  
      /**
       * Returns the long value of a date created by the given integer values.<p>
       *
       * @param year the integer value of year
       * @param month the integer value of month
       * @param date the integer value of date
       *
       * @return the long value of a date created by the given integer values
       */
      public static long parseDate(int year, int month, int date) {
  
          Calendar calendar = Calendar.getInstance();
          calendar.set(year, month, date);
          return calendar.getTime().getTime();
      }
  
      /**
       * Parses a formated date and time string in HTTP-Header date format and returns the
       * time value.<p>
       *
       * @param timestamp the timestamp in HTTP-Header date format
       * @return time value as long
       * @throws ParseException if parsing fails
       */
      synchronized public static long parseHeaderDate(String timestamp) throws ParseException {
  
          return HEADER_DEFAULT.parse(timestamp).getTime();
      }
  }