/**
* Copyright (C) 2011 JTalks.org Team
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jtalks.jcommune.plugin.api.web.velocity.tool;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import java.util.Locale;
import java.util.concurrent.TimeUnit;
/**
* Custom tool to format {@link org.joda.time.DateTime} object in velocity templates.
* {@link org.apache.velocity.tools.generic.DateTool} not supports {@link org.joda.time.DateTime}
* see <a href="https://issues.apache.org/jira/browse/VELTOOLS-135">VELTOOLS-135</a>
*
* @author Mikhail Stryzhonok
*/
public class JodaDateTimeTool {
private static final String DATE_FORMAT_PATTERN = "dd MMM yyyy HH:mm";
public static final String GMT_COOKIE_NAME = "GMT";
public static final int DEFAULT_OFFSET = 0;
private DateTimeFormatter formatter = DateTimeFormat.forPattern(DATE_FORMAT_PATTERN);
private long offset = DEFAULT_OFFSET;
public JodaDateTimeTool(HttpServletRequest request) {
if (request != null) {
Cookie[] cookies = request.getCookies();
if (cookies != null) {
for (Cookie cookie : cookies) {
if (cookie.getName().equals(GMT_COOKIE_NAME)) {
offset = this.convertTimeZoneOffset(cookie.getValue());
break;
}
}
}
}
}
/**
* Represents dateTime object as string in specified locale and user's timezone.
* Example: 01 Jan 2011 05:13
*
* @param dateTime Date and time to be converted to string
* @param locale locale to be used
* @return dateTime string representation
*/
public String format(DateTime dateTime, Locale locale) {
if (dateTime == null) {
return "";
}
DateTimeZone timeZone = dateTime.getZone();
long utcTime = timeZone.convertLocalToUTC(dateTime.getMillis(), false);
dateTime = new DateTime(utcTime + offset);
return formatter.withLocale(locale).print(dateTime);
}
/**
* Converts timezone offset representation to millisecond offset.
* If timezone offset representation is incorrect, then GMT
* timezone value is used.
*
* @param jsRepresentation time difference between GMT and
* local time, in minutes. Example: "-120"
* @return signed millisecond timezone offset
*/
private long convertTimeZoneOffset(String jsRepresentation) {
try {
int offsetInMinutes = -Integer.parseInt(jsRepresentation);
return TimeUnit.MINUTES.toMillis(offsetInMinutes);
} catch (NumberFormatException e) {
// someone has passed wrong offset in cookie, use GMT
return DEFAULT_OFFSET;
}
}
}