Java tutorial
/* * Copyright 2004-2008 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.codehaus.groovy.grails.web.converters.marshaller.json; import grails.converters.JSON; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.codehaus.groovy.grails.commons.GrailsDomainClass; import org.codehaus.groovy.grails.commons.GrailsDomainClassProperty; import org.codehaus.groovy.grails.commons.GrailsClassUtils; import org.codehaus.groovy.grails.web.converters.ConverterUtil; import org.codehaus.groovy.grails.web.converters.exceptions.ConverterException; import org.codehaus.groovy.grails.web.converters.marshaller.ObjectMarshaller; import org.codehaus.groovy.grails.web.json.JSONWriter; import org.hibernate.collection.AbstractPersistentCollection; import org.hibernate.Hibernate; import org.springframework.beans.BeanWrapper; import org.springframework.beans.BeanWrapperImpl; import java.util.*; /** * @author Siegfried Puchbauer * @since 1.1 */ public class DomainClassMarshaller implements ObjectMarshaller<JSON> { private final Log log = LogFactory.getLog(getClass()); private boolean includeVersion = false; public DomainClassMarshaller(boolean includeVersion) { this.includeVersion = includeVersion; } public boolean isIncludeVersion() { return includeVersion; } public void setIncludeVersion(boolean includeVersion) { this.includeVersion = includeVersion; } public boolean supports(Object object) { return ConverterUtil.isDomainClass(object.getClass()); } public void marshalObject(Object value, JSON json) throws ConverterException { JSONWriter writer = json.getWriter(); Class clazz = value.getClass(); GrailsDomainClass domainClass = ConverterUtil.getDomainClass(clazz.getName()); BeanWrapper beanWrapper = new BeanWrapperImpl(value); writer.object(); writer.key("class").value(domainClass.getClazz().getName()); GrailsDomainClassProperty id = domainClass.getIdentifier(); Object idValue = extractValue(value, id); json.property("id", idValue); if (isIncludeVersion()) { GrailsDomainClassProperty versionProperty = domainClass.getVersion(); Object version = extractValue(value, versionProperty); json.property("version", version); } GrailsDomainClassProperty[] properties = domainClass.getPersistentProperties(); for (GrailsDomainClassProperty property : properties) { writer.key(property.getName()); if (!property.isAssociation()) { // Write non-relation property Object val = beanWrapper.getPropertyValue(property.getName()); json.convertAnother(val); } else { Object referenceObject = beanWrapper.getPropertyValue(property.getName()); if (isRenderDomainClassRelations()) { if (referenceObject == null) { writer.value(null); } else { if (referenceObject instanceof AbstractPersistentCollection) { // Force initialisation and get a non-persistent Collection Type AbstractPersistentCollection acol = (AbstractPersistentCollection) referenceObject; acol.forceInitialization(); if (referenceObject instanceof SortedMap) { referenceObject = new TreeMap((SortedMap) referenceObject); } else if (referenceObject instanceof SortedSet) { referenceObject = new TreeSet((SortedSet) referenceObject); } else if (referenceObject instanceof Set) { referenceObject = new HashSet((Set) referenceObject); } else if (referenceObject instanceof Map) { referenceObject = new HashMap((Map) referenceObject); } else { referenceObject = new ArrayList((Collection) referenceObject); } } else if (!Hibernate.isInitialized(referenceObject)) { Hibernate.initialize(referenceObject); } json.convertAnother(referenceObject); } } else { if (referenceObject == null) { json.value(null); } else { GrailsDomainClass referencedDomainClass = property.getReferencedDomainClass(); // Embedded are now always fully rendered if (referencedDomainClass == null || property.isEmbedded() || GrailsClassUtils.isJdk5Enum(property.getType())) { json.convertAnother(referenceObject); } else if (property.isOneToOne() || property.isManyToOne() || property.isEmbedded()) { asShortObject(referenceObject, json, referencedDomainClass.getIdentifier(), referencedDomainClass); } else { GrailsDomainClassProperty referencedIdProperty = referencedDomainClass.getIdentifier(); String refPropertyName = referencedDomainClass.getPropertyName(); if (referenceObject instanceof Collection) { Collection o = (Collection) referenceObject; writer.array(); for (Object el : o) { asShortObject(el, json, referencedIdProperty, referencedDomainClass); } writer.endArray(); } else if (referenceObject instanceof Map) { Map<Object, Object> map = (Map<Object, Object>) referenceObject; for (Map.Entry<Object, Object> entry : map.entrySet()) { String key = String.valueOf(entry.getKey()); Object o = entry.getValue(); writer.object(); writer.key(key); asShortObject(o, json, referencedIdProperty, referencedDomainClass); writer.endObject(); } } } } } } } writer.endObject(); } protected void asShortObject(Object refObj, JSON json, GrailsDomainClassProperty idProperty, GrailsDomainClass referencedDomainClass) throws ConverterException { JSONWriter writer = json.getWriter(); writer.object(); writer.key("class").value(referencedDomainClass.getName()); writer.key("id").value(extractValue(refObj, idProperty)); writer.endObject(); } protected Object extractValue(Object domainObject, GrailsDomainClassProperty property) { BeanWrapper beanWrapper = new BeanWrapperImpl(domainObject); return beanWrapper.getPropertyValue(property.getName()); } protected boolean isRenderDomainClassRelations() { return false; } }