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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    *   http://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.handler.codec.AsciiString;
19  
20  import java.util.HashMap;
21  import java.util.Map;
22  
23  /**
24   * The request method of HTTP or its derived protocols, such as
25   * <a href="http://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
26   * <a href="http://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>.
27   */
28  public class HttpMethod implements Comparable<HttpMethod> {
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("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("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("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("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("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("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("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("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("CONNECT");
87  
88      private static final Map<String, HttpMethod> methodMap =
89              new HashMap<String, HttpMethod>();
90  
91      static {
92          methodMap.put(OPTIONS.toString(), OPTIONS);
93          methodMap.put(GET.toString(), GET);
94          methodMap.put(HEAD.toString(), HEAD);
95          methodMap.put(POST.toString(), POST);
96          methodMap.put(PUT.toString(), PUT);
97          methodMap.put(PATCH.toString(), PATCH);
98          methodMap.put(DELETE.toString(), DELETE);
99          methodMap.put(TRACE.toString(), TRACE);
100         methodMap.put(CONNECT.toString(), CONNECT);
101     }
102 
103     /**
104      * Returns the {@link HttpMethod} represented by the specified name.
105      * If the specified name is a standard HTTP method name, a cached instance
106      * will be returned.  Otherwise, a new instance will be returned.
107      */
108     public static HttpMethod valueOf(String name) {
109         if (name == null) {
110             throw new NullPointerException("name");
111         }
112 
113         name = name.trim();
114         if (name.isEmpty()) {
115             throw new IllegalArgumentException("empty name");
116         }
117 
118         HttpMethod result = methodMap.get(name);
119         if (result != null) {
120             return result;
121         } else {
122             return new HttpMethod(name);
123         }
124     }
125 
126     private final AsciiString name;
127     private final String nameAsString;
128 
129     /**
130      * Creates a new HTTP method with the specified name.  You will not need to
131      * create a new method unless you are implementing a protocol derived from
132      * HTTP, such as
133      * <a href="http://en.wikipedia.org/wiki/Real_Time_Streaming_Protocol">RTSP</a> and
134      * <a href="http://en.wikipedia.org/wiki/Internet_Content_Adaptation_Protocol">ICAP</a>
135      */
136     public HttpMethod(String name) {
137         if (name == null) {
138             throw new NullPointerException("name");
139         }
140 
141         name = name.trim();
142         if (name.isEmpty()) {
143             throw new IllegalArgumentException("empty name");
144         }
145 
146         for (int i = 0; i < name.length(); i ++) {
147             char c = name.charAt(i);
148             if (Character.isISOControl(c) || Character.isWhitespace(c)) {
149                 throw new IllegalArgumentException("invalid character in name");
150             }
151         }
152 
153         this.name = new AsciiString(name);
154         nameAsString = name;
155     }
156 
157     /**
158      * Returns the name of this method.
159      */
160     public AsciiString name() {
161         return name;
162     }
163 
164     @Override
165     public int hashCode() {
166         return name().hashCode();
167     }
168 
169     @Override
170     public boolean equals(Object o) {
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 nameAsString;
182     }
183 
184     @Override
185     public int compareTo(HttpMethod o) {
186         return name().compareTo(o.name());
187     }
188 }