/*
* $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/protocol/HttpDateGenerator.java $
* $Revision: 548066 $
* $Date: 2007-06-17 09:51:55 -0700 (Sun, 17 Jun 2007) $
*
* ====================================================================
* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.http.protocol;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
import java.util.TimeZone;
/**
* Generates a date in the format required by the HTTP protocol.
*
* @author <a href="mailto:oleg at ural.ru">Oleg Kalnichevski</a>
*
* @version $Revision: 548066 $
*
* @since 4.0
*/
public class HttpDateGenerator {
/** Date format pattern used to generate the header in RFC 1123 format. */
public static final
String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss zzz";
/** The time zone to use in the date header. */
public static final TimeZone GMT = TimeZone.getTimeZone("GMT");
private final DateFormat dateformat;
private long dateAsLong = 0L;
private String dateAsText = null;
public HttpDateGenerator() {
super();
this.dateformat = new SimpleDateFormat(PATTERN_RFC1123, Locale.US);
this.dateformat.setTimeZone(GMT);
}
public synchronized String getCurrentDate() {
long now = System.currentTimeMillis();
if (now - this.dateAsLong > 1000) {
// Generate new date string
this.dateAsText = this.dateformat.format(new Date(now));
this.dateAsLong = now;
}
return this.dateAsText;
}
}