org.argeo.jcr/src/org/argeo/jcr/DefaultJcrListener.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *         http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16 package org.argeo.jcr;
  17
  18 import javax.jcr.RepositoryException;
  19 import javax.jcr.Session;
  20 import javax.jcr.observation.Event;
  21 import javax.jcr.observation.EventIterator;
  22 import javax.jcr.observation.EventListener;
  23 import javax.jcr.observation.ObservationManager;
  24
  25 import org.apache.commons.logging.Log;
  26 import org.apache.commons.logging.LogFactory;
  27
  28 /** To be overridden */
  29 public class DefaultJcrListener implements EventListener {
  30         private final static Log log = LogFactory.getLog(DefaultJcrListener.class);
  31         private Session session;
  32         private String path = "/";
  33         private Boolean deep = true;
  34
  35         public void start() {
  36                 try {
  37                         addEventListener(session().getWorkspace().getObservationManager());
  38                         if (log.isDebugEnabled())
  39                                 log.debug("Registered JCR event listener on " + path);
  40                 } catch (Exception e) {
  41                         throw new ArgeoJcrException("Cannot register event listener", e);
  42                 }
  43         }
  44
  45         public void stop() {
  46                 try {
  47                         session().getWorkspace().getObservationManager()
  48                                         .removeEventListener(this);
  49                         if (log.isDebugEnabled())
  50                                 log.debug("Unregistered JCR event listener on " + path);
  51                 } catch (Exception e) {
  52                         throw new ArgeoJcrException("Cannot unregister event listener", e);
  53                 }
  54         }
  55
  56         /** Default is listen to all events */
  57         protected Integer getEvents() {
  58                 return Event.NODE_ADDED | Event.NODE_REMOVED | Event.PROPERTY_ADDED
  59                                 | Event.PROPERTY_CHANGED | Event.PROPERTY_REMOVED;
  60         }
  61
  62         /** To be overidden */
  63         public void onEvent(EventIterator events) {
  64                 while (events.hasNext()) {
  65                         Event event = events.nextEvent();
  66                         log.debug(event);
  67                 }
  68         }
  69
  70         /** To be overidden */
  71         protected void addEventListener(ObservationManager observationManager)
  72                         throws RepositoryException {
  73                 observationManager.addEventListener(this, getEvents(), path, deep,
  74                                 null, null, false);
  75         }
  76
  77         private Session session() {
  78                 return session;
  79         }
  80
  81         public void setPath(String path) {
  82                 this.path = path;
  83         }
  84
  85         public void setDeep(Boolean deep) {
  86                 this.deep = deep;
  87         }
  88
  89         public void setSession(Session session) {
  90                 this.session = session;
  91         }
  92
  93 }