001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.rest.client2; 014 015import java.io.*; 016 017import org.apache.http.*; 018import org.apache.http.client.*; 019import org.apache.http.client.methods.*; 020import org.apache.http.protocol.*; 021import org.apache.juneau.*; 022 023/** 024 * Interface that allows you to override the handling of HTTP requests. 025 * 026 * <p class='w900'> 027 * Providing this implementation is the equivalent to overriding the {@link RestClient#execute(HttpHost,HttpRequest,HttpContext)}. 028 * <br>This can also be accomplished by providing your own {@link RestClientBuilder#connectionManager(org.apache.http.conn.HttpClientConnectionManager) connection manager} 029 * or subclassing {@link RestClient}, but this provides a simpler way of handling the requests yourself. 030 * 031 * <p> 032 * The constructor on the implementation class can optionally take in any of the following parameters: 033 * <ul> 034 * <li>{@link RestClient} - The client using this handler. 035 * <li>{@link PropertyStore} - The properties used to initialize the client. 036 * </ul> 037 * 038 * <p> 039 * The {@link BasicRestCallHandler} shows an example of a simple pass-through handler. Note that you must handle 040 * the case where {@link HttpHost} is null. 041 * 042 * <p class='bcode w800'> 043 * <jk>public class</jk> BasicRestCallHandler <jk>implements</jk> RestCallHandler { 044 * 045 * <jk>private final</jk> RestClient <jf>client</jf>; 046 * 047 * <jk>public</jk> BasicRestCallHandler(RestClient <jv>client</jv>) { 048 * <jk>this</jk>.<jf>client</jf> = <jv>client</jv>; 049 * } 050 * 051 * <ja>@Override</ja> 052 * <jk>public</jk> HttpResponse run(HttpHost <jv>target</jv>, HttpRequest <jv>request</jv>, HttpContext <jv>context</jv>) <jk>throws</jk> IOException { 053 * <jk>if</jk> (<jv>target</jv> == <jk>null</jk>) 054 * <jk>return</jk> <jf>client</jf>.execute((HttpUriRequest)<jv>request</jv>, <jv>context</jv>); 055 * <jk>return</jk> <jf>client</jf>.execute(<jv>target</jv>, <jv>request</jv>, <jv>context</jv>); 056 * } 057 * } 058 * </p> 059 * 060 * <ul class='seealso'> 061 * <li class='jf'>{@link RestClient#RESTCLIENT_callHandler} 062 * <li class='jm'>{@link RestClientBuilder#callHandler(Class)} 063 * <li class='jm'>{@link RestClientBuilder#callHandler(RestCallHandler)} 064 * </ul> 065 */ 066public interface RestCallHandler { 067 068 /** 069 * Execute the specified request. 070 * 071 * <p> 072 * Subclasses can override this method to provide specialized handling. 073 * 074 * @param target The target host for the request. 075 * <br>Implementations may accept <jk>null</jk> if they can still determine a route, for example to a default 076 * target or by inspecting the request. 077 * @param request The request to execute. Must be an instance of {@link HttpUriRequest} if the target is <jk>null</jk>. 078 * @param context The context to use for the execution, or <jk>null</jk> to use the default context. 079 * @return 080 * The response to the request. 081 * <br>This is always a final response, never an intermediate response with an 1xx status code. 082 * <br>Whether redirects or authentication challenges will be returned or handled automatically depends on the 083 * implementation and configuration of this client. 084 * @throws IOException In case of a problem or the connection was aborted. 085 * @throws ClientProtocolException In case of an http protocol error. 086 */ 087 HttpResponse run(HttpHost target, HttpRequest request, HttpContext context) throws ClientProtocolException, IOException; 088}