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