1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.http.client.methods;
29
30 import java.net.URI;
31 import java.util.HashSet;
32 import java.util.Set;
33
34 import org.apache.http.Header;
35 import org.apache.http.HeaderElement;
36 import org.apache.http.HeaderIterator;
37 import org.apache.http.HttpResponse;
38 import org.apache.http.util.Args;
39
40 /**
41 * HTTP OPTIONS method.
42 * <p>
43 * The HTTP OPTIONS method is defined in section 9.2 of
44 * <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>:
45 * </p>
46 * <blockquote>
47 * The OPTIONS method represents a request for information about the
48 * communication options available on the request/response chain
49 * identified by the Request-URI. This method allows the client to
50 * determine the options and/or requirements associated with a resource,
51 * or the capabilities of a server, without implying a resource action
52 * or initiating a resource retrieval.
53 * </blockquote>
54 *
55 * @since 4.0
56 */
57 public class HttpOptions extends HttpRequestBase {
58
59 public final static String METHOD_NAME = "OPTIONS";
60
61 public HttpOptions() {
62 super();
63 }
64
65 public HttpOptions(final URI uri) {
66 super();
67 setURI(uri);
68 }
69
70 /**
71 * @throws IllegalArgumentException if the uri is invalid.
72 */
73 public HttpOptions(final String uri) {
74 super();
75 setURI(URI.create(uri));
76 }
77
78 @Override
79 public String getMethod() {
80 return METHOD_NAME;
81 }
82
83 public Set<String> getAllowedMethods(final HttpResponse response) {
84 Args.notNull(response, "HTTP response");
85
86 final HeaderIterator it = response.headerIterator("Allow");
87 final Set<String> methods = new HashSet<String>();
88 while (it.hasNext()) {
89 final Header header = it.nextHeader();
90 final HeaderElement[] elements = header.getElements();
91 for (final HeaderElement element : elements) {
92 methods.add(element.getName());
93 }
94 }
95 return methods;
96 }
97
98 }