001 package de.deepamehta.core.impl;
002
003 import de.deepamehta.core.Association;
004 import de.deepamehta.core.AssociationType;
005 import de.deepamehta.core.DeepaMehtaObject;
006 import de.deepamehta.core.ChildTopics;
007 import de.deepamehta.core.RelatedTopic;
008 import de.deepamehta.core.Topic;
009 import de.deepamehta.core.TopicType;
010 import de.deepamehta.core.service.Directives;
011
012 import com.sun.jersey.spi.container.ContainerRequest;
013 import com.sun.jersey.spi.container.ContainerResponse;
014 import com.sun.jersey.spi.container.ContainerResponseFilter;
015
016 import java.lang.reflect.Type;
017 import java.lang.reflect.ParameterizedType;
018 import java.util.List;
019 import java.util.logging.Logger;
020
021
022
023 class JerseyResponseFilter implements ContainerResponseFilter {
024
025 // ---------------------------------------------------------------------------------------------- Instance Variables
026
027 private EmbeddedService dms;
028
029 private Logger logger = Logger.getLogger(getClass().getName());
030
031 // ---------------------------------------------------------------------------------------------------- Constructors
032
033 JerseyResponseFilter(EmbeddedService dms) {
034 this.dms = dms;
035 }
036
037 // -------------------------------------------------------------------------------------------------- Public Methods
038
039 @Override
040 public ContainerResponse filter(ContainerRequest request, ContainerResponse response) {
041 try {
042 dms.fireEvent(CoreEvent.SERVICE_RESPONSE_FILTER, response);
043 //
044 Object entity = response.getEntity();
045 boolean includeChilds = getIncludeChilds(request);
046 boolean includeAssocChilds = getIncludeAssocChilds(request);
047 if (entity != null) {
048 //
049 // 1) Loading child topics
050 if (entity instanceof DeepaMehtaObject) {
051 loadChildTopics((DeepaMehtaObject) entity, includeChilds, includeAssocChilds);
052 } else if (isIterable(response, DeepaMehtaObject.class)) {
053 loadChildTopics((Iterable<DeepaMehtaObject>) entity, includeChilds, includeAssocChilds);
054 }
055 //
056 // 2) Firing PRE_SEND events
057 if (entity instanceof TopicType) { // Note: must take precedence over topic
058 firePreSend((TopicType) entity);
059 } else if (entity instanceof AssociationType) {
060 firePreSend((AssociationType) entity); // Note: must take precedence over topic
061 } else if (entity instanceof Topic) {
062 firePreSend((Topic) entity);
063 } else if (entity instanceof Association) {
064 firePreSend((Association) entity);
065 } else if (entity instanceof Directives) {
066 // Note: some plugins rely on the PRE_SEND event in order to enrich updated objects, others don't.
067 // E.g. the Access Control plugin must enrich updated objects with permission information.
068 // ### TODO: check if this is still required. Meanwhile permissions are not an enrichment anymore.
069 // ### Update: Yes, it is still required, e.g. by the Time plugin when enriching with timestamps.
070 firePreSend((Directives) entity);
071 } else if (isIterable(response, TopicType.class)) {
072 firePreSendTopicTypes((Iterable<TopicType>) entity);
073 } else if (isIterable(response, AssociationType.class)) {
074 firePreSendAssociationTypes((Iterable<AssociationType>) entity);
075 } else if (isIterable(response, Topic.class)) {
076 firePreSendTopics((Iterable<Topic>) entity);
077 // ### FIXME: for Iterable<Association> no PRE_SEND_ASSOCIATION events are fired
078 }
079 }
080 //
081 logger.fine("### Removing tread-local directives");
082 Directives.remove();
083 //
084 return response;
085 } catch (Exception e) {
086 throw new RuntimeException("Jersey response filtering failed", e);
087 }
088 }
089
090 // ------------------------------------------------------------------------------------------------- Private Methods
091
092 // === Loading child topics ===
093
094 private void loadChildTopics(DeepaMehtaObject object, boolean includeChilds,
095 boolean includeAssocChilds) {
096 if (includeChilds) {
097 object.loadChildTopics();
098 if (includeAssocChilds) {
099 loadRelatingAssociationChildTopics(object);
100 }
101 }
102 }
103
104 private void loadChildTopics(Iterable<DeepaMehtaObject> objects, boolean includeChilds,
105 boolean includeAssocChilds) {
106 if (includeChilds) {
107 for (DeepaMehtaObject object : objects) {
108 object.loadChildTopics();
109 }
110 if (includeAssocChilds) {
111 for (DeepaMehtaObject object : objects) {
112 loadRelatingAssociationChildTopics(object);
113 }
114 }
115 }
116 }
117
118 // ---
119
120 private void loadRelatingAssociationChildTopics(DeepaMehtaObject object) {
121 ChildTopics childTopics = object.getChildTopics();
122 for (String childTypeUri : childTopics) {
123 Object value = childTopics.get(childTypeUri);
124 if (value instanceof RelatedTopic) {
125 RelatedTopic childTopic = (RelatedTopic) value;
126 childTopic.getRelatingAssociation().loadChildTopics();
127 loadRelatingAssociationChildTopics(childTopic); // recursion
128 } else if (value instanceof List) {
129 for (RelatedTopic childTopic : (List<RelatedTopic>) value) {
130 childTopic.getRelatingAssociation().loadChildTopics();
131 loadRelatingAssociationChildTopics(childTopic); // recursion
132 }
133 } else {
134 throw new RuntimeException("Unexpected \"" + childTypeUri + "\" value in ChildTopics: " + value);
135 }
136 }
137 }
138
139 // === Firing PRE_SEND events ===
140
141 private void firePreSend(Topic topic) {
142 dms.fireEvent(CoreEvent.PRE_SEND_TOPIC, topic);
143 }
144
145 private void firePreSend(Association assoc) {
146 dms.fireEvent(CoreEvent.PRE_SEND_ASSOCIATION, assoc);
147 }
148
149 private void firePreSend(TopicType topicType) {
150 dms.fireEvent(CoreEvent.PRE_SEND_TOPIC_TYPE, topicType);
151 }
152
153 private void firePreSend(AssociationType assocType) {
154 dms.fireEvent(CoreEvent.PRE_SEND_ASSOCIATION_TYPE, assocType);
155 }
156
157 private void firePreSend(Directives directives) {
158 for (Directives.Entry entry : directives) {
159 switch (entry.dir) {
160 case UPDATE_TOPIC:
161 firePreSend((Topic) entry.arg);
162 break;
163 case UPDATE_ASSOCIATION:
164 firePreSend((Association) entry.arg);
165 break;
166 case UPDATE_TOPIC_TYPE:
167 firePreSend((TopicType) entry.arg);
168 break;
169 case UPDATE_ASSOCIATION_TYPE:
170 firePreSend((AssociationType) entry.arg);
171 break;
172 }
173 }
174 }
175
176 private void firePreSendTopics(Iterable<Topic> topics) {
177 for (Topic topic : topics) {
178 firePreSend(topic);
179 }
180 }
181
182 private void firePreSendTopicTypes(Iterable<TopicType> topicTypes) {
183 for (TopicType topicType : topicTypes) {
184 firePreSend(topicType);
185 }
186 }
187
188 private void firePreSendAssociationTypes(Iterable<AssociationType> assocTypes) {
189 for (AssociationType assocType : assocTypes) {
190 firePreSend(assocType);
191 }
192 }
193
194 // === Helper ===
195
196 private boolean isIterable(ContainerResponse response, Class elementType) {
197 Type genericType = response.getEntityType();
198 if (genericType instanceof ParameterizedType) {
199 Type[] typeArgs = ((ParameterizedType) genericType).getActualTypeArguments();
200 Class<?> type = response.getEntity().getClass();
201 if (typeArgs.length == 1 && Iterable.class.isAssignableFrom(type) &&
202 elementType.isAssignableFrom((Class) typeArgs[0])) {
203 return true;
204 }
205 }
206 return false;
207 }
208
209 // ---
210
211 private boolean getIncludeChilds(ContainerRequest request) {
212 return getBooleanQueryParameter(request, "include_childs");
213 }
214
215 private boolean getIncludeAssocChilds(ContainerRequest request) {
216 return getBooleanQueryParameter(request, "include_assoc_childs");
217 }
218
219 // ---
220
221 private boolean getBooleanQueryParameter(ContainerRequest request, String param) {
222 return Boolean.parseBoolean(request.getQueryParameters().getFirst(param));
223 }
224 }