001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
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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// *                                                                                                                         *
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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>From</l> HTTP request header.
021 *
022 * <p>
023 * The email address of the user making the request.
024 *
025 * <h5 class='figure'>Example</h5>
026 * <p class='bcode w800'>
027 *    From: user@example.com
028 * </p>
029 *
030 * <h5 class='topic'>RFC2616 Specification</h5>
031 *
032 * The From request-header field, if given, SHOULD contain an Internet e-mail address for the human user who controls
033 * the requesting user agent.
034 * The address SHOULD be machine-usable, as defined by "mailbox" in RFC 822 [9] as updated by RFC 1123 [8]:
035 *
036 * <p class='bcode w800'>
037 *    From   = "From" ":" mailbox
038 * </p>
039 *
040 * <p>
041 * An example is:
042 * <p class='bcode w800'>
043 *    From: webmaster@w3.org
044 * </p>
045 *
046 * <p>
047 * This header field MAY be used for logging purposes and as a means for identifying the source of invalid or unwanted
048 * requests.
049 * It SHOULD NOT be used as an insecure form of access protection.
050 * The interpretation of this field is that the request is being performed on behalf of the person given, who accepts
051 * responsibility for the method performed.
052 * In particular, robot agents SHOULD include this header so that the person responsible for running the robot can be
053 * contacted if problems occur on the receiving end.
054 *
055 * <p>
056 * The Internet e-mail address in this field MAY be separate from the Internet host which issued the request.
057 * For example, when a request is passed through a proxy the original issuer's address SHOULD be used.
058 *
059 * <p>
060 * The client SHOULD NOT send the From header field without the user's approval, as it might conflict with the user's
061 * privacy interests or their site's security policy.
062 * It is strongly recommended that the user be able to disable, enable, and modify the value of this field at any time
063 * prior to a request.
064 *
065 * <ul class='seealso'>
066 *    <li class='extlink'>{@doc ExtRFC2616}
067 * </ul>
068 */
069@Header("From")
070public class From extends BasicStringHeader {
071
072   private static final long serialVersionUID = 1L;
073
074   /**
075    * Convenience creator.
076    *
077    * @param value
078    *    The header value.
079    *    <br>Can be any of the following:
080    *    <ul>
081    *       <li>{@link String}
082    *       <li>Anything else - Converted to <c>String</c> then parsed.
083    *    </ul>
084    * @return A new {@link From} object.
085    */
086   public static From of(Object value) {
087      if (value == null)
088         return null;
089      return new From(value);
090   }
091
092   /**
093    * Convenience creator using supplier.
094    *
095    * <p>
096    * Header value is re-evaluated on each call to {@link #getValue()}.
097    *
098    * @param value
099    *    The header value supplier.
100    *    <br>Can be any of the following:
101    *    <ul>
102    *       <li>{@link String}
103    *       <li>Anything else - Converted to <c>String</c> then parsed.
104    *    </ul>
105    * @return A new {@link From} object.
106    */
107   public static From of(Supplier<?> value) {
108      if (value == null)
109         return null;
110      return new From(value);
111   }
112
113   /**
114    * Constructor.
115    *
116    * @param value
117    *    The header value.
118    *    <br>Can be any of the following:
119    *    <ul>
120    *       <li>{@link String}
121    *       <li>Anything else - Converted to <c>String</c> then parsed.
122    *       <li>A {@link Supplier} of anything on this list.
123    *    </ul>
124    */
125   public From(Object value) {
126      super("From", value);
127   }
128
129   /**
130    * Constructor
131    *
132    * @param value
133    *    The header value.
134    */
135   public From(String value) {
136      this((Object)value);
137   }
138}