001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.http.header;
014
015import java.util.function.*;
016
017import org.apache.juneau.http.annotation.*;
018
019/**
020 * Represents a parsed <l>Server</l> HTTP response header.
021 *
022 * <p>
023 * A name for the server.
024 *
025 * <h5 class='figure'>Example</h5>
026 * <p class='bcode'>
027 *    Server: Apache/2.4.1 (Unix)
028 * </p>
029 *
030 * <h5 class='topic'>RFC2616 Specification</h5>
031 *
032 * The Server response-header field contains information about the software used by the origin server to handle the
033 * request.
034 * The field can contain multiple product tokens (section 3.8) and comments identifying the server and any significant
035 * sub-products.
036 * The product tokens are listed in order of their significance for identifying the application.
037 *
038 * <p class='bcode'>
039 *    Server         = "Server" ":" 1*( product | comment )
040 * </p>
041 *
042 * <p>
043 * Example:
044 * <p class='bcode'>
045 *    Server: CERN/3.0 libwww/2.17
046 * </p>
047 *
048 * <p>
049 * If the response is being forwarded through a proxy, the proxy application MUST NOT modify the Server response-header.
050 * Instead, it SHOULD include a Via field (as described in section 14.45).
051 *
052 * <p>
053 * Note: Revealing the specific software version of the server might allow the server machine to become more vulnerable
054 * to attacks against software that is known to contain security holes.
055 * Server implementors are encouraged to make this field a configurable option.
056 *
057 * <h5 class='section'>See Also:</h5><ul>
058 *    <li class='link'><a class="doclink" href="../../../../../index.html#juneau-rest-common">juneau-rest-common</a>
059 *    <li class='extlink'><a class="doclink" href="https://www.w3.org/Protocols/rfc2616/rfc2616.html">Hypertext Transfer Protocol -- HTTP/1.1</a>
060 * </ul>
061 *
062 * @serial exclude
063 */
064@Header("Server")
065public class Server extends BasicStringHeader {
066
067   //-----------------------------------------------------------------------------------------------------------------
068   // Static
069   //-----------------------------------------------------------------------------------------------------------------
070
071   private static final long serialVersionUID = 1L;
072   private static final String NAME = "Server";
073
074   /**
075    * Static creator.
076    *
077    * @param value
078    *    The header value.
079    *    <br>Can be <jk>null</jk>.
080    * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>.
081    */
082   public static Server of(String value) {
083      return value == null ? null : new Server(value);
084   }
085
086   /**
087    * Static creator with delayed value.
088    *
089    * <p>
090    * Header value is re-evaluated on each call to {@link #getValue()}.
091    *
092    * @param value
093    *    The supplier of the header value.
094    *    <br>Can be <jk>null</jk>.
095    * @return A new header bean, or <jk>null</jk> if the value is <jk>null</jk>.
096    */
097   public static Server of(Supplier<String> value) {
098      return value == null ? null : new Server(value);
099   }
100
101   //-----------------------------------------------------------------------------------------------------------------
102   // Instance
103   //-----------------------------------------------------------------------------------------------------------------
104
105   /**
106    * Constructor.
107    *
108    * @param value
109    *    The header value.
110    *    <br>Can be <jk>null</jk>.
111    */
112   public Server(String value) {
113      super(NAME, value);
114   }
115
116   /**
117    * Constructor with delayed value.
118    *
119    * <p>
120    * Header value is re-evaluated on each call to {@link #getValue()}.
121    *
122    * @param value
123    *    The supplier of the header value.
124    *    <br>Can be <jk>null</jk>.
125    */
126   public Server(Supplier<String> value) {
127      super(NAME, value);
128   }
129}