001/* 002 * (C) Copyright 2015 Nuxeo SA (http://nuxeo.com/) and others. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 * 016 * Contributors: 017 * Nicolas Chapurlat <nchapurlat@nuxeo.com> 018 */ 019 020package org.nuxeo.ecm.core.io.marshallers.json; 021 022import static javax.ws.rs.core.MediaType.APPLICATION_JSON_TYPE; 023import static org.nuxeo.ecm.core.io.registry.MarshallingConstants.ENTITY_FIELD_NAME; 024 025import java.io.IOException; 026import java.lang.reflect.Type; 027import java.util.List; 028import java.util.Map; 029 030import org.apache.commons.lang3.reflect.TypeUtils; 031import org.codehaus.jackson.JsonGenerator; 032import org.nuxeo.ecm.automation.core.util.Paginable; 033import org.nuxeo.ecm.core.api.DocumentModelList; 034import org.nuxeo.ecm.core.io.registry.MarshallerRegistry; 035import org.nuxeo.ecm.core.io.registry.Writer; 036import org.nuxeo.ecm.core.io.registry.context.RenderingContext; 037import org.nuxeo.ecm.platform.query.api.Aggregate; 038import org.nuxeo.ecm.platform.query.api.Bucket; 039 040/** 041 * Base class to convert {@link List} as json. 042 * <p> 043 * It follow the classic Nuxeo list format : 044 * 045 * <pre> 046 * { 047 * "entity-type": "GIVEN_ENTITY_TYPE", 048 * <-- pagination info if available are here. 049 * "entries": [ 050 * {...}, <-- A {@link Writer} must be able to manage this format. 051 * {...}, 052 * ... 053 * {...} 054 * ] 055 * } 056 * </pre> 057 * <p> 058 * This list generates pagination information if the list is a {@link Paginable}. 059 * </p> 060 * <p> 061 * This reader delegates the marshalling of entries to the {@link MarshallerRegistry}. A Json {@link Writer} compatible 062 * with the required type must be registered. 063 * </p> 064 * 065 * @param <EntityType> The type of the element of this list. 066 * @since 7.2 067 */ 068public abstract class DefaultListJsonWriter<EntityType> extends AbstractJsonWriter<List<EntityType>> { 069 070 /** 071 * The "entity-type" of the list. 072 */ 073 private final String entityType; 074 075 /** 076 * The Java type of the element of this list. 077 */ 078 private final Class<EntityType> elClazz; 079 080 /** 081 * The generic type of the element of this list. 082 */ 083 private final Type elGenericType; 084 085 /** 086 * Use this constructor if the element of the list are not based on Java generic type. 087 * 088 * @param entityType The list "entity-type". 089 * @param elClazz The class of the element of the list. 090 */ 091 public DefaultListJsonWriter(String entityType, Class<EntityType> elClazz) { 092 super(); 093 this.entityType = entityType; 094 this.elClazz = elClazz; 095 this.elGenericType = elClazz; 096 } 097 098 /** 099 * Use this constructor if the element of the list are based on Java generic type. 100 * 101 * @param entityType The list "entity-type". 102 * @param elClazz The class of the element of the list. 103 * @param elGenericType The generic type of the list (you can use {@link TypeUtils#parameterize(Class, Type...) to 104 * generate it} 105 */ 106 public DefaultListJsonWriter(String entityType, Class<EntityType> elClazz, Type elGenericType) { 107 super(); 108 this.entityType = entityType; 109 this.elClazz = elClazz; 110 this.elGenericType = elGenericType; 111 } 112 113 @Override 114 public void write(List<EntityType> list, JsonGenerator jg) throws IOException { 115 jg.writeStartObject(); 116 ctx.setParameterValues(RenderingContext.RESPONSE_HEADER_ENTITY_TYPE_KEY, this.entityType); 117 jg.writeStringField(ENTITY_FIELD_NAME, entityType); 118 writePaginationInfos(list, jg); 119 Writer<EntityType> documentWriter = registry.getWriter(ctx, elClazz, elGenericType, APPLICATION_JSON_TYPE); 120 jg.writeArrayFieldStart("entries"); 121 for (EntityType entity : list) { 122 documentWriter.write(entity, elClazz, elClazz, APPLICATION_JSON_TYPE, new OutputStreamWithJsonWriter(jg)); 123 } 124 jg.writeEndArray(); 125 extend(list, jg); 126 jg.writeEndObject(); 127 } 128 129 private void writePaginationInfos(List<EntityType> list, JsonGenerator jg) throws IOException { 130 if (list instanceof Paginable) { 131 Paginable<?> paginable = (Paginable<?>) list; 132 jg.writeBooleanField("isPaginable", true); 133 jg.writeNumberField("resultsCount", paginable.getResultsCount()); 134 jg.writeNumberField("pageSize", paginable.getPageSize()); 135 jg.writeNumberField("maxPageSize", paginable.getMaxPageSize()); 136 jg.writeNumberField("currentPageSize", paginable.getCurrentPageSize()); 137 jg.writeNumberField("currentPageIndex", paginable.getCurrentPageIndex()); 138 jg.writeNumberField("numberOfPages", paginable.getNumberOfPages()); 139 jg.writeBooleanField("isPreviousPageAvailable", paginable.isPreviousPageAvailable()); 140 jg.writeBooleanField("isNextPageAvailable", paginable.isNextPageAvailable()); 141 jg.writeBooleanField("isLastPageAvailable", paginable.isLastPageAvailable()); 142 jg.writeBooleanField("isSortable", paginable.isSortable()); 143 jg.writeBooleanField("hasError", paginable.hasError()); 144 jg.writeStringField("errorMessage", paginable.getErrorMessage()); 145 // compat fields 146 if (paginable instanceof DocumentModelList) { 147 jg.writeNumberField("totalSize", ((DocumentModelList) paginable).totalSize()); 148 } 149 jg.writeNumberField("pageIndex", paginable.getCurrentPageIndex()); 150 jg.writeNumberField("pageCount", paginable.getNumberOfPages()); 151 if (paginable.hasAggregateSupport()) { 152 Map<String, Aggregate<? extends Bucket>> aggregates = paginable.getAggregates(); 153 if (aggregates != null && !paginable.getAggregates().isEmpty()) { 154 jg.writeObjectField("aggregations", paginable.getAggregates()); 155 } 156 } 157 } 158 } 159 160 /** 161 * Override this method to write additional information in the list. 162 * 163 * @param list The list to marshal. 164 * @param jg The {@link JsonGenerator} which point inside the list object at the end of standard properties. 165 * @since 7.2 166 */ 167 protected void extend(List<EntityType> list, JsonGenerator jg) throws IOException { 168 } 169 170}