/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.felix.ipojo.handler.wbp;
import java.lang.reflect.InvocationTargetException;
import org.apache.felix.ipojo.PrimitiveHandler;
import org.apache.felix.ipojo.util.Callback;
import org.apache.felix.ipojo.util.Tracker;
import org.apache.felix.ipojo.util.TrackerCustomizer;
import org.osgi.framework.Filter;
import org.osgi.framework.ServiceReference;
/**
* Manage a white board pattern.
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class WhiteBoardManager implements TrackerCustomizer {
/**
* The monitored filter.
*/
private Filter m_filter;
/**
* The onArrival method.
*/
private Callback m_onArrival;
/**
* The onDeparture method.
*/
private Callback m_onDeparture;
/**
* The onModify method.
*/
private Callback m_onModification;
/**
* The service tracker.
*/
private Tracker m_tracker;
/**
* The attached handler.
*/
private PrimitiveHandler m_handler;
/**
* Constructor.
* @param handler the attached handler
* @param filter the monitored filter
* @param bind the onArrival method
* @param unbind the onDeparture method
* @param modification the onModify method
*/
public WhiteBoardManager(WhiteBoardPatternHandler handler, Filter filter, String bind, String unbind, String modification) {
m_handler = handler;
m_onArrival = new Callback(bind, new Class[] {ServiceReference.class}, false, m_handler.getInstanceManager());
m_onDeparture = new Callback(unbind, new Class[] {ServiceReference.class}, false, m_handler.getInstanceManager());
if (modification != null) {
m_onModification = new Callback(modification, new Class[] {ServiceReference.class}, false, m_handler.getInstanceManager());
}
m_filter = filter;
m_tracker = new Tracker(handler.getInstanceManager().getContext(), m_filter, this);
}
/**
* Opens the tracker.
*/
public void start() {
// Calling several times open is no-effect.
m_tracker.open();
}
/**
* Closes the tracker.
*/
public void stop() {
m_tracker.close();
}
/**
* A new service was added to the tracker.
* @param arg0 the service reference.
* @see org.apache.felix.ipojo.util.TrackerCustomizer#addedService(org.osgi.framework.ServiceReference)
*/
public void addedService(ServiceReference arg0) {
try {
m_onArrival.call(new Object[] {arg0});
} catch (NoSuchMethodException e) {
m_handler.error("The onArrival method " + m_onArrival.getMethod() + " does not exist in the class", e);
m_handler.getInstanceManager().stop();
} catch (IllegalAccessException e) {
m_handler.error("The onArrival method " + m_onArrival.getMethod() + " cannot be invoked", e);
m_handler.getInstanceManager().stop();
} catch (InvocationTargetException e) {
m_handler.error("The onArrival method " + m_onArrival.getMethod() + " has thrown an exception", e.getTargetException());
m_handler.getInstanceManager().stop();
}
}
/**
* A new service is detected.
* @param arg0 the service reference
* @return {@code true} to add the service.
* @see org.apache.felix.ipojo.util.TrackerCustomizer#addingService(org.osgi.framework.ServiceReference)
*/
public boolean addingService(ServiceReference arg0) {
return true;
}
/**
* An existing service was modified.
* @param arg0 the service reference
* @param arg1 the service object (if already get)
* @see org.apache.felix.ipojo.util.TrackerCustomizer#modifiedService(org.osgi.framework.ServiceReference, java.lang.Object)
*/
public void modifiedService(ServiceReference arg0, Object arg1) {
if (m_onModification != null) {
try {
m_onModification.call(new Object[] {arg0});
} catch (NoSuchMethodException e) {
m_handler.error("The onModification method " + m_onModification.getMethod() + " does not exist in the class", e);
m_handler.getInstanceManager().stop();
} catch (IllegalAccessException e) {
m_handler.error("The onModification method " + m_onModification.getMethod() + " cannot be invoked", e);
m_handler.getInstanceManager().stop();
} catch (InvocationTargetException e) {
m_handler.error("The onModification method " + m_onModification.getMethod() + " has thrown an exception", e.getTargetException());
m_handler.getInstanceManager().stop();
}
}
}
/**
* A service disappears.
* @param arg0 the service reference
* @param arg1 the service object (if already get)
* @see org.apache.felix.ipojo.util.TrackerCustomizer#removedService(org.osgi.framework.ServiceReference, java.lang.Object)
*/
public void removedService(ServiceReference arg0, Object arg1) {
try {
m_onDeparture.call(new Object[] {arg0});
} catch (NoSuchMethodException e) {
m_handler.error("The onDeparture method " + m_onDeparture.getMethod() + " does not exist in the class", e);
m_handler.getInstanceManager().stop();
} catch (IllegalAccessException e) {
m_handler.error("The onDeparture method " + m_onDeparture.getMethod() + " cannot be invoked", e);
m_handler.getInstanceManager().stop();
} catch (InvocationTargetException e) {
m_handler.error("The onDeparture method " + m_onDeparture.getMethod() + " has thrown an exception", e.getTargetException());
m_handler.getInstanceManager().stop();
}
}
}