Java tutorial
/* * ==================================================================== * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. * */ package org.apache.http.client.methods; import java.net.URI; import java.util.HashSet; import java.util.Set; import org.apache.http.Header; import org.apache.http.HeaderElement; import org.apache.http.HeaderIterator; import org.apache.http.HttpResponse; import org.apache.http.annotation.NotThreadSafe; import org.apache.http.util.Args; /** * HTTP OPTIONS method. * <p> * The HTTP OPTIONS method is defined in section 9.2 of * <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC2616</a>: * <blockquote> * The OPTIONS method represents a request for information about the * communication options available on the request/response chain * identified by the Request-URI. This method allows the client to * determine the options and/or requirements associated with a resource, * or the capabilities of a server, without implying a resource action * or initiating a resource retrieval. * </blockquote> * </p> * * @since 4.0 */ @NotThreadSafe public class HttpOptions extends HttpRequestBase { public final static String METHOD_NAME = "OPTIONS"; public HttpOptions() { super(); } public HttpOptions(final URI uri) { super(); setURI(uri); } /** * @throws IllegalArgumentException if the uri is invalid. */ public HttpOptions(final String uri) { super(); setURI(URI.create(uri)); } @Override public String getMethod() { return METHOD_NAME; } public Set<String> getAllowedMethods(final HttpResponse response) { Args.notNull(response, "HTTP response"); final HeaderIterator it = response.headerIterator("Allow"); final Set<String> methods = new HashSet<String>(); while (it.hasNext()) { final Header header = it.nextHeader(); final HeaderElement[] elements = header.getElements(); for (final HeaderElement element : elements) { methods.add(element.getName()); } } return methods; } }