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.converters; 014 015import static org.apache.juneau.rest.HttpRuntimeException.*; 016 017import org.apache.juneau.*; 018import org.apache.juneau.rest.*; 019import org.apache.juneau.http.exception.*; 020import org.apache.juneau.transform.*; 021import org.apache.juneau.utils.*; 022 023/** 024 * Converter for enabling of {@link PojoRest} support on response objects returned by a <c>@RestMethod</c> method. 025 * 026 * <p> 027 * When enabled, objects in a POJO tree returned by the REST method can be addressed through additional URL path 028 * information. 029 * 030 * <p class='bcode w800'> 031 * <jc>// Resource method on resource "http://localhost:8080/sample/addressBook"</jc> 032 * <ja>@RestMethod</ja>(name=<jsf>GET</jsf>, converters=Traversable.<jk>class</jk>) 033 * <jk>public void</jk> doGet(RestRequest req, RestResponse res) { 034 * <jk>return new</jk> AddressBook(); 035 * } 036 * 037 * <jc>// Sample usage</jc> 038 * <jk>public static void</jk> main(String[] args) { 039 * <jc>// Get the zip code of the 2nd address of the first person in the address book.</jc> 040 * RestCall r = <jk>new</jk> RestClient().doGet(<js>"http://localhost:8080/sample/addressBook/0/addresses/1/zip"</js>); 041 * <jk>int</jk> zip = r.getResponse(Integer.<jk>class</jk>); 042 * } 043 * </p> 044 * 045 * <ul class='seealso'> 046 * <li class='jc'>{@link PojoRest} - Additional information on addressing elements in a POJO tree using URL notation. 047 * <li class='jf'>{@link RestContext#REST_converters} - Registering converters with REST resources. 048 * <li class='link'>{@doc RestConverters} 049 * </ul> 050 */ 051public final class Traversable implements RestConverter { 052 053 @Override /* RestConverter */ 054 @SuppressWarnings({"rawtypes", "unchecked"}) 055 public Object convert(RestRequest req, Object o) throws HttpException, InternalServerError { 056 if (o == null) 057 return null; 058 059 String pathRemainder = req.getPathMatch().getRemainder(); 060 061 if (pathRemainder != null) { 062 try { 063 BeanSession bs = req.getBeanSession(); 064 PojoSwap swap = bs.getClassMetaForObject(o).getSwap(bs); 065 if (swap != null) 066 o = swap.swap(bs, o); 067 PojoRest p = new PojoRest(o, req.getBody().getReaderParser()); 068 o = p.get(pathRemainder); 069 } catch (PojoRestException e) { 070 throw new HttpException(e, e.getStatus()); 071 } catch (Throwable t) { 072 throw toHttpException(t, InternalServerError.class); 073 } 074 } 075 076 return o; 077 } 078}