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 * Creates a {@link RestRequest} object based on the specified incoming {@link HttpServletRequest} object. 042 * 043 * @param req The request object from the {@link #service(HttpServletRequest, HttpServletResponse)} method. 044 * @return The wrapped request object. 045 * @throws ServletException If any errors occur trying to interpret the request. 046 */ 047 public RestRequest createRequest(HttpServletRequest req) throws ServletException; 048 049 /** 050 * Creates a {@link RestResponse} object based on the specified incoming {@link HttpServletResponse} object 051 * and the request returned by {@link #createRequest(HttpServletRequest)}. 052 * 053 * @param req The request object returned by {@link #createRequest(HttpServletRequest)}. 054 * @param res The response object from the {@link #service(HttpServletRequest, HttpServletResponse)} method. 055 * @return The wrapped response object. 056 * @throws ServletException If any errors occur trying to interpret the request or response. 057 */ 058 public RestResponse createResponse(RestRequest req, HttpServletResponse res) throws ServletException; 059 060 /** 061 * The main service method. 062 * 063 * @param r1 The incoming HTTP servlet request object. 064 * @param r2 The incoming HTTP servlet response object. 065 * @throws ServletException Error occurred. 066 * @throws IOException Thrown by underlying stream. 067 */ 068 public void service(HttpServletRequest r1, HttpServletResponse r2) throws ServletException, IOException; 069 070 /** 071 * The main method for serializing POJOs passed in through the {@link RestResponse#setOutput(Object)} method or 072 * returned by the Java method. 073 * 074 * @param req The HTTP request. 075 * @param res The HTTP response. 076 * @throws Exception Can be thrown if error occurred while handling response. 077 */ 078 public void handleResponse(RestRequest req, RestResponse res) throws Exception; 079 080 /** 081 * Handle the case where a matching method was not found. 082 * 083 * @param rc The HTTP response code. 084 * @param req The HTTP request. 085 * @param res The HTTP response. 086 * @throws Exception Can be thrown if error occurred while handling response. 087 */ 088 public void handleNotFound(int rc, RestRequest req, RestResponse res) throws Exception; 089 090 /** 091 * Method for handling response errors. 092 * 093 * @param req The servlet request. 094 * @param res The servlet response. 095 * @param e The exception that occurred. 096 * @throws Exception Can be thrown if error occurred while handling response. 097 */ 098 public void handleError(HttpServletRequest req, HttpServletResponse res, Throwable e) throws Exception; 099 100 /** 101 * Method for converting thrown exceptions into other types before they are handled. 102 * 103 * @param t The thrown object. 104 * @return The converted thrown object. 105 */ 106 public Throwable convertThrowable(Throwable t); 107 108 /** 109 * Returns the session objects for the specified request. 110 * 111 * @param req The REST request. 112 * @param res The REST response. 113 * @return The session objects for that request. 114 */ 115 public Map<String,Object> getSessionObjects(RestRequest req, RestResponse res); 116}