org.argeo.server.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 import org.argeo.ArgeoException;
  28
  29 /** To be overridden */
  30 public class DefaultJcrListener implements EventListener {
  31         private final static Log log = LogFactory.getLog(DefaultJcrListener.class);
  32         private Session session;
  33         private String path = "/";
  34         private Boolean deep = true;
  35
  36         public void start() {
  37                 try {
  38                         addEventListener(session().getWorkspace().getObservationManager());
  39                         if (log.isDebugEnabled())
  40                                 log.debug("Registered JCR event listener on " + path);
  41                 } catch (Exception e) {
  42                         throw new ArgeoException("Cannot register event listener", e);
  43                 }
  44         }
  45
  46         public void stop() {
  47                 try {
  48                         session().getWorkspace().getObservationManager()
  49                                         .removeEventListener(this);
  50                         if (log.isDebugEnabled())
  51                                 log.debug("Unregistered JCR event listener on " + path);
  52                 } catch (Exception e) {
  53                         throw new ArgeoException("Cannot unregister event listener", e);
  54                 }
  55         }
  56
  57         /** Default is listen to all events */
  58         protected Integer getEvents() {
  59                 return Event.NODE_ADDED | Event.NODE_REMOVED | Event.PROPERTY_ADDED
  60                                 | Event.PROPERTY_CHANGED | Event.PROPERTY_REMOVED;
  61         }
  62
  63         /** To be overidden */
  64         public void onEvent(EventIterator events) {
  65                 while (events.hasNext()) {
  66                         Event event = events.nextEvent();
  67                         log.debug(event);
  68                 }
  69         }
  70
  71         /** To be overidden */
  72         protected void addEventListener(ObservationManager observationManager)
  73                         throws RepositoryException {
  74                 observationManager.addEventListener(this, getEvents(), path, deep,
  75                                 null, null, false);
  76         }
  77
  78         private Session session() {
  79                 return session;
  80         }
  81
  82         public void setPath(String path) {
  83                 this.path = path;
  84         }
  85
  86         public void setDeep(Boolean deep) {
  87                 this.deep = deep;
  88         }
  89
  90         public void setSession(Session session) {
  91                 this.session = session;
  92         }
  93
  94 }