001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.juneau.http.header;
018
019import java.util.function.*;
020
021import org.apache.juneau.http.annotation.*;
022
023/**
024 * Represents a parsed <l>Server</l> HTTP response header.
025 *
026 * <p>
027 * A name for the server.
028 *
029 * <h5 class='figure'>Example</h5>
030 * <p class='bcode'>
031 *    Server: Apache/2.4.1 (Unix)
032 * </p>
033 *
034 * <h5 class='topic'>RFC2616 Specification</h5>
035 *
036 * The Server response-header field contains information about the software used by the origin server to handle the
037 * request.
038 * The field can contain multiple product tokens (section 3.8) and comments identifying the server and any significant
039 * sub-products.
040 * The product tokens are listed in order of their significance for identifying the application.
041 *
042 * <p class='bcode'>
043 *    Server         = "Server" ":" 1*( product | comment )
044 * </p>
045 *
046 * <p>
047 * Example:
048 * <p class='bcode'>
049 *    Server: CERN/3.0 libwww/2.17
050 * </p>
051 *
052 * <p>
053 * If the response is being forwarded through a proxy, the proxy application MUST NOT modify the Server response-header.
054 * Instead, it SHOULD include a Via field (as described in section 14.45).
055 *
056 * <p>
057 * Note: Revealing the specific software version of the server might allow the server machine to become more vulnerable
058 * to attacks against software that is known to contain security holes.
059 * Server implementors are encouraged to make this field a configurable option.
060 *
061 * <h5 class='section'>See Also:</h5><ul>
062 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauRestCommonBasics">juneau-rest-common Basics</a>
063 *    <li class='extlink'><a class="doclink" href="https://www.w3.org/Protocols/rfc2616/rfc2616.html">Hypertext Transfer Protocol -- HTTP/1.1</a>
064 * </ul>
065 *
066 * @serial exclude
067 */
068@Header("Server")
069public class Server extends BasicStringHeader {
070   private static final long serialVersionUID = 1L;
071   private static final String NAME = "Server";
072
073   /**
074    * Static creator.
075    *
076    * @param value
077    *    The header value.
078    *    <br>Can be <jk>null</jk>.
079    * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>.
080    */
081   public static Server of(String value) {
082      return value == null ? null : new Server(value);
083   }
084
085   /**
086    * Static creator with delayed value.
087    *
088    * <p>
089    * Header value is re-evaluated on each call to {@link #getValue()}.
090    *
091    * @param value
092    *    The supplier of the header value.
093    *    <br>Can be <jk>null</jk>.
094    * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>.
095    */
096   public static Server of(Supplier<String> value) {
097      return value == null ? null : new Server(value);
098   }
099
100   /**
101    * Constructor.
102    *
103    * @param value
104    *    The header value.
105    *    <br>Can be <jk>null</jk>.
106    */
107   public Server(String value) {
108      super(NAME, value);
109   }
110
111   /**
112    * Constructor with delayed value.
113    *
114    * <p>
115    * Header value is re-evaluated on each call to {@link #getValue()}.
116    *
117    * @param value
118    *    The supplier of the header value.
119    *    <br>Can be <jk>null</jk>.
120    */
121   public Server(Supplier<String> value) {
122      super(NAME, value);
123   }
124}