org.apache.juneau.http.LastModified Maven / Gradle / Ivy
// ***************************************************************************************************************************
// * 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. *
// ***************************************************************************************************************************
package org.apache.juneau.http;
/**
* Represents a parsed Last-Modified HTTP response header.
*
*
* The last modified date for the requested object (in "HTTP-date" format as defined by RFC 7231).
*
*
Example
*
* Last-Modified: Tue, 15 Nov 1994 12:45:26 GMT
*
*
* RFC2616 Specification
*
* The Last-Modified entity-header field indicates the date and time at which the origin server believes the variant was
* last modified.
*
*
* Last-Modified = "Last-Modified" ":" HTTP-date
*
*
*
* An example of its use is...
*
* Last-Modified: Tue, 15 Nov 1994 12:45:26 GMT
*
*
*
* The exact meaning of this header field depends on the implementation of the origin server and the nature of the
* original resource.
* For files, it may be just the file system last-modified time.
* For entities with dynamically included parts, it may be the most recent of the set of last-modify times for its
* component parts.
* For database gateways, it may be the last-update time stamp of the record.
* For virtual objects, it may be the last time the internal state changed.
*
*
* An origin server MUST NOT send a Last-Modified date which is later than the server's time of message origination.
* In such cases, where the resource's last modification would indicate some time in the future, the server MUST replace
* that date with the message origination date.
*
*
* An origin server SHOULD obtain the Last-Modified value of the entity as close as possible to the time that it
* generates the Date value of its response.
* This allows a recipient to make an accurate assessment of the entity's modification time, especially if the entity
* changes near the time that the response is generated.
*
*
* HTTP/1.1 servers SHOULD send Last-Modified whenever feasible.
*
*
Additional Information
*
*/
public final class LastModified extends HeaderDate {
/**
* Returns a parsed Last-Modified header.
*
* @param value The Last-Modified header string.
* @return The parsed Last-Modified header, or null if the string was null.
*/
public static LastModified forString(String value) {
if (value == null)
return null;
return new LastModified(value);
}
private LastModified(String value) {
super(value);
}
}