001/* 002 * ==================================================================== 003 * Licensed to the Apache Software Foundation (ASF) under one 004 * or more contributor license agreements. See the NOTICE file 005 * distributed with this work for additional information 006 * regarding copyright ownership. The ASF licenses this file 007 * to you under the Apache License, Version 2.0 (the 008 * "License"); you may not use this file except in compliance 009 * with the License. You may obtain a copy of the License at 010 * 011 * http://www.apache.org/licenses/LICENSE-2.0 012 * 013 * Unless required by applicable law or agreed to in writing, 014 * software distributed under the License is distributed on an 015 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 016 * KIND, either express or implied. See the License for the 017 * specific language governing permissions and limitations 018 * under the License. 019 * ==================================================================== 020 * 021 * This software consists of voluntary contributions made by many 022 * individuals on behalf of the Apache Software Foundation. For more 023 * information on the Apache Software Foundation, please see 024 * <http://www.apache.org/>. 025 * 026 */ 027 028package org.apache.http.client.methods; 029 030import java.net.URI; 031import java.util.HashSet; 032import java.util.Set; 033 034import org.apache.http.Header; 035import org.apache.http.HeaderElement; 036import org.apache.http.HeaderIterator; 037import org.apache.http.HttpResponse; 038import org.apache.http.util.Args; 039 040/** 041 * HTTP OPTIONS method. 042 * <p> 043 * The HTTP OPTIONS method is defined in section 9.2 of 044 * <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>: 045 * </p> 046 * <blockquote> 047 * The OPTIONS method represents a request for information about the 048 * communication options available on the request/response chain 049 * identified by the Request-URI. This method allows the client to 050 * determine the options and/or requirements associated with a resource, 051 * or the capabilities of a server, without implying a resource action 052 * or initiating a resource retrieval. 053 * </blockquote> 054 * 055 * @since 4.0 056 */ 057public class HttpOptions extends HttpRequestBase { 058 059 public final static String METHOD_NAME = "OPTIONS"; 060 061 public HttpOptions() { 062 super(); 063 } 064 065 public HttpOptions(final URI uri) { 066 super(); 067 setURI(uri); 068 } 069 070 /** 071 * @throws IllegalArgumentException if the uri is invalid. 072 */ 073 public HttpOptions(final String uri) { 074 super(); 075 setURI(URI.create(uri)); 076 } 077 078 @Override 079 public String getMethod() { 080 return METHOD_NAME; 081 } 082 083 public Set<String> getAllowedMethods(final HttpResponse response) { 084 Args.notNull(response, "HTTP response"); 085 086 final HeaderIterator it = response.headerIterator("Allow"); 087 final Set<String> methods = new HashSet<String>(); 088 while (it.hasNext()) { 089 final Header header = it.nextHeader(); 090 final HeaderElement[] elements = header.getElements(); 091 for (final HeaderElement element : elements) { 092 methods.add(element.getName()); 093 } 094 } 095 return methods; 096 } 097 098}