001 package de.deepamehta.core.impl;
002
003 import de.deepamehta.core.Association;
004 import de.deepamehta.core.AssociationType;
005 import de.deepamehta.core.Topic;
006 import de.deepamehta.core.TopicType;
007 import de.deepamehta.core.service.ClientState;
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 if (entity != null) {
044 ClientState clientState = clientState(request);
045 if (entity instanceof TopicType) { // Note: must take precedence over topic
046 firePreSend((TopicType) entity, clientState);
047 } else if (entity instanceof AssociationType) {
048 firePreSend((AssociationType) entity, clientState); // Note: must take precedence over topic
049 } else if (entity instanceof Topic) {
050 firePreSend((Topic) entity, clientState);
051 } else if (entity instanceof Association) {
052 firePreSend((Association) entity, clientState);
053 } else if (entity instanceof Directives) {
054 // Note: some plugins rely on the PRE_SEND event in order to enrich updated objects, others don't.
055 // E.g. the Access Control plugin must enrich updated objects with permission information.
056 firePreSend((Directives) entity, clientState);
057 } else if (isIterable(response, TopicType.class)) {
058 firePreSendTopicTypes((Iterable<TopicType>) entity, clientState);
059 } else if (isIterable(response, AssociationType.class)) {
060 firePreSendAssociationTypes((Iterable<AssociationType>) entity, clientState);
061 } else if (isIterable(response, Topic.class)) {
062 firePreSendTopics((Iterable<Topic>) entity, clientState);
063 }
064 }
065 return response;
066 } catch (Exception e) {
067 throw new RuntimeException("Jersey response filtering failed", e);
068 }
069 }
070
071 // ------------------------------------------------------------------------------------------------- Private Methods
072
073 private void firePreSend(Topic topic, ClientState clientState) {
074 dms.fireEvent(CoreEvent.PRE_SEND_TOPIC, topic, clientState);
075 }
076
077 private void firePreSend(Association assoc, ClientState clientState) {
078 dms.fireEvent(CoreEvent.PRE_SEND_ASSOCIATION, assoc, clientState);
079 }
080
081 private void firePreSend(TopicType topicType, ClientState clientState) {
082 dms.fireEvent(CoreEvent.PRE_SEND_TOPIC_TYPE, topicType, clientState);
083 }
084
085 private void firePreSend(AssociationType assocType, ClientState clientState) {
086 dms.fireEvent(CoreEvent.PRE_SEND_ASSOCIATION_TYPE, assocType, clientState);
087 }
088
089 private void firePreSend(Directives directives, ClientState clientState) {
090 for (Directives.Entry entry : directives) {
091 switch (entry.dir) {
092 case UPDATE_TOPIC:
093 firePreSend((Topic) entry.arg, clientState);
094 break;
095 case UPDATE_ASSOCIATION:
096 firePreSend((Association) entry.arg, clientState);
097 break;
098 case UPDATE_TOPIC_TYPE:
099 firePreSend((TopicType) entry.arg, clientState);
100 break;
101 case UPDATE_ASSOCIATION_TYPE:
102 firePreSend((AssociationType) entry.arg, clientState);
103 break;
104 }
105 }
106 }
107
108 private void firePreSendTopics(Iterable<Topic> topics, ClientState clientState) {
109 for (Topic topic : topics) {
110 firePreSend(topic, clientState);
111 }
112 }
113
114 private void firePreSendTopicTypes(Iterable<TopicType> topicTypes, ClientState clientState) {
115 for (TopicType topicType : topicTypes) {
116 firePreSend(topicType, clientState);
117 }
118 }
119
120 private void firePreSendAssociationTypes(Iterable<AssociationType> assocTypes, ClientState clientState) {
121 for (AssociationType assocType : assocTypes) {
122 firePreSend(assocType, clientState);
123 }
124 }
125
126 // ---
127
128 private boolean isIterable(ContainerResponse response, Class elementType) {
129 Type genericType = response.getEntityType();
130 if (genericType instanceof ParameterizedType) {
131 Type[] typeArgs = ((ParameterizedType) genericType).getActualTypeArguments();
132 Class<?> type = response.getEntity().getClass();
133 if (typeArgs.length == 1 && Iterable.class.isAssignableFrom(type) &&
134 elementType.isAssignableFrom((Class) typeArgs[0])) {
135 return true;
136 }
137 }
138 return false;
139 }
140
141 private ClientState clientState(ContainerRequest request) {
142 List<String> cookies = request.getRequestHeader("Cookie");
143 if (cookies == null) {
144 return new ClientState(null);
145 }
146 // ### FIXME: does this happen?
147 if (cookies.size() > 1) {
148 throw new RuntimeException("Request contains more than one Cookie header");
149 }
150 //
151 return new ClientState(cookies.get(0));
152 }
153 }