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; 014 015 016import java.io.*; 017import java.util.*; 018 019import javax.servlet.*; 020import javax.servlet.http.*; 021 022/** 023 * Class that handles the basic lifecycle of an HTTP REST call. 024 * 025 * <ul class='seealso'> 026 * <li class='jf'>{@link RestContext#REST_callHandler} 027 * </ul> 028 */ 029public interface RestCallHandler { 030 031 /** 032 * Represents no RestCallHandler. 033 * 034 * <p> 035 * Used on annotation to indicate that the value should be inherited from the parent class, and 036 * ultimately {@link BasicRestCallHandler} if not specified at any level. 037 */ 038 public interface Null extends RestCallHandler {} 039 040 /** 041 * The main service method. 042 * 043 * @param r1 The incoming HTTP servlet request object. 044 * @param r2 The incoming HTTP servlet response object. 045 * @throws ServletException Error occurred. 046 * @throws IOException Thrown by underlying stream. 047 */ 048 public void service(HttpServletRequest r1, HttpServletResponse r2) throws ServletException, IOException; 049 050 /** 051 * Wraps an incoming servlet request/response pair into a single {@link RestCall} object. 052 * 053 * @param req The rest request. 054 * @param res The rest response. 055 * @return The wrapped request/response pair. 056 */ 057 public RestCall createCall(HttpServletRequest req, HttpServletResponse res); 058 059 /** 060 * Creates a {@link RestRequest} object based on the specified incoming {@link HttpServletRequest} object. 061 * 062 * @param call The current REST call. 063 * @return The wrapped request object. 064 * @throws ServletException If any errors occur trying to interpret the request. 065 */ 066 public RestRequest createRequest(RestCall call) throws ServletException; 067 068 /** 069 * Creates a {@link RestResponse} object based on the specified incoming {@link HttpServletResponse} object 070 * and the request returned by {@link #createRequest(RestCall)}. 071 * 072 * @param call The current REST call. 073 * @return The wrapped response object. 074 * @throws ServletException If any errors occur trying to interpret the request or response. 075 */ 076 public RestResponse createResponse(RestCall call) throws ServletException; 077 078 /** 079 * The main method for serializing POJOs passed in through the {@link RestResponse#setOutput(Object)} method or 080 * returned by the Java method. 081 * 082 * @param call The current REST call. 083 * @throws Exception Can be thrown if error occurred while handling response. 084 */ 085 public void handleResponse(RestCall call) throws Exception; 086 087 /** 088 * Handle the case where a matching method was not found. 089 * 090 * @param call The current REST call. 091 * @throws Exception Can be thrown if error occurred while handling response. 092 */ 093 public void handleNotFound(RestCall call) throws Exception; 094 095 /** 096 * Method for handling response errors. 097 * 098 * @param call The current REST call. 099 * @param e The exception that occurred. 100 * @throws Exception Can be thrown if error occurred while handling response. 101 */ 102 public void handleError(RestCall call, Throwable e) throws Exception; 103 104 /** 105 * Method for converting thrown exceptions into other types before they are handled. 106 * 107 * @param t The thrown object. 108 * @return The converted thrown object. 109 */ 110 public Throwable convertThrowable(Throwable t); 111 112 /** 113 * Returns the session objects for the specified request. 114 * 115 * @param req The REST request. 116 * @param res The REST response. 117 * @return The session objects for that request. 118 */ 119 public Map<String,Object> getSessionObjects(RestRequest req, RestResponse res); 120}