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1   /*
2    * Copyright 2012 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   https://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.handler.codec.http;
17  
18  import io.netty.util.AsciiString;
19  
20  import static io.netty.util.internal.ObjectUtil.checkNotNull;
21  
22  /**
23   * The request method of HTTP or its derived protocols, such as
24   * <a href="https://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
25   * <a href="https://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>.
26   */
27  public class HttpMethod implements Comparable<HttpMethod> {
28  
29      /**
30       * The OPTIONS method represents a request for information about the communication options
31       * available on the request/response chain identified by the Request-URI. This method allows
32       * the client to determine the options and/or requirements associated with a resource, or the
33       * capabilities of a server, without implying a resource action or initiating a resource
34       * retrieval.
35       */
36      public static final HttpMethod OPTIONS = new HttpMethod(AsciiString.cached("OPTIONS"));
37  
38      /**
39       * The GET method means retrieve whatever information (in the form of an entity) is identified
40       * by the Request-URI.  If the Request-URI refers to a data-producing process, it is the
41       * produced data which shall be returned as the entity in the response and not the source text
42       * of the process, unless that text happens to be the output of the process.
43       */
44      public static final HttpMethod GET = new HttpMethod(AsciiString.cached("GET"));
45  
46      /**
47       * The HEAD method is identical to GET except that the server MUST NOT return a message-body
48       * in the response.
49       */
50      public static final HttpMethod HEAD = new HttpMethod(AsciiString.cached("HEAD"));
51  
52      /**
53       * The POST method is used to request that the origin server accept the entity enclosed in the
54       * request as a new subordinate of the resource identified by the Request-URI in the
55       * Request-Line.
56       */
57      public static final HttpMethod POST = new HttpMethod(AsciiString.cached("POST"));
58  
59      /**
60       * The PUT method requests that the enclosed entity be stored under the supplied Request-URI.
61       */
62      public static final HttpMethod PUT = new HttpMethod(AsciiString.cached("PUT"));
63  
64      /**
65       * The PATCH method requests that a set of changes described in the
66       * request entity be applied to the resource identified by the Request-URI.
67       */
68      public static final HttpMethod PATCH = new HttpMethod(AsciiString.cached("PATCH"));
69  
70      /**
71       * The DELETE method requests that the origin server delete the resource identified by the
72       * Request-URI.
73       */
74      public static final HttpMethod DELETE = new HttpMethod(AsciiString.cached("DELETE"));
75  
76      /**
77       * The TRACE method is used to invoke a remote, application-layer loop- back of the request
78       * message.
79       */
80      public static final HttpMethod TRACE = new HttpMethod(AsciiString.cached("TRACE"));
81  
82      /**
83       * This specification reserves the method name CONNECT for use with a proxy that can dynamically
84       * switch to being a tunnel
85       */
86      public static final HttpMethod CONNECT = new HttpMethod(AsciiString.cached("CONNECT"));
87  
88      /**
89       * The QUERY method requests that the request target process the enclosed content in a safe and
90       * idempotent manner and then respond with the result of that processing.
91       */
92      public static final HttpMethod QUERY = new HttpMethod(AsciiString.cached("QUERY"));
93  
94      /**
95       * Returns the {@link HttpMethod} represented by the specified name.
96       * If the specified name is a standard HTTP method name, a cached instance
97       * will be returned.  Otherwise, a new instance will be returned.
98       */
99      public static HttpMethod valueOf(String name) {
100         switch (name) {
101             case "OPTIONS": return HttpMethod.OPTIONS;
102             case "GET":     return HttpMethod.GET;
103             case "HEAD":    return HttpMethod.HEAD;
104             case "POST":    return HttpMethod.POST;
105             case "PUT":     return HttpMethod.PUT;
106             case "PATCH":   return HttpMethod.PATCH;
107             case "DELETE":  return HttpMethod.DELETE;
108             case "TRACE":   return HttpMethod.TRACE;
109             case "CONNECT": return HttpMethod.CONNECT;
110             case "QUERY":   return HttpMethod.QUERY;
111             default:        return new HttpMethod(name);
112         }
113     }
114 
115     private final AsciiString name;
116 
117     /**
118      * Private constructor for the built-in constants defined in this class.
119      * The names are compiler-controlled literals that are already valid HTTP tokens,
120      * so there is no need to validate or trim them at runtime.
121      */
122     private HttpMethod(AsciiString name) {
123         this.name = name;
124     }
125 
126     /**
127      * Creates a new HTTP method with the specified name.  You will not need to
128      * create a new method unless you are implementing a protocol derived from
129      * HTTP, such as
130      * <a href="https://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
131      * <a href="https://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>
132      */
133     public HttpMethod(String name) {
134         checkNotNull(name, "name");
135         // The name must be non-empty and contain only valid HTTP token characters.
136         if (name.isEmpty()) {
137             throw new IllegalArgumentException("name cannot be empty");
138         }
139         int index = HttpHeaderValidationUtil.validateToken(name);
140         if (index != -1) {
141             throw new IllegalArgumentException(
142                     "Illegal character in HTTP Method: 0x" + Integer.toHexString(name.charAt(index)));
143         }
144         this.name = AsciiString.cached(name);
145     }
146 
147     /**
148      * Returns the name of this method.
149      */
150     public String name() {
151         return name.toString();
152     }
153 
154     /**
155      * Returns the name of this method.
156      */
157     public AsciiString asciiName() {
158         return name;
159     }
160 
161     @Override
162     public int hashCode() {
163         return name().hashCode();
164     }
165 
166     @Override
167     public boolean equals(Object o) {
168         if (this == o) {
169             return true;
170         }
171         if (!(o instanceof HttpMethod)) {
172             return false;
173         }
174 
175         HttpMethod that = (HttpMethod) o;
176         return name().equals(that.name());
177     }
178 
179     @Override
180     public String toString() {
181         return name.toString();
182     }
183 
184     @Override
185     public int compareTo(HttpMethod o) {
186         if (o == this) {
187             return 0;
188         }
189         return name().compareTo(o.name());
190     }
191 
192 }