| /* |
| * 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.util; |
| |
| import org.apache.felix.ipojo.ContextListener; |
| import org.apache.felix.ipojo.ContextSource; |
| |
| import java.util.*; |
| |
| /** |
| * A context source giving access to system properties. |
| */ |
| public class InstanceConfigurationSource implements ContextSource { |
| |
| /** |
| * The instance configuration. |
| */ |
| private Dictionary<String,Object> m_configuration; |
| |
| /** |
| * Listener list. |
| */ |
| private List<ContextListener> m_listeners = new ArrayList<ContextListener>(); |
| |
| public InstanceConfigurationSource(Dictionary<String, Object> configuration) { |
| m_configuration = configuration; |
| } |
| |
| /** |
| * The instance is reconfigured. |
| * Changes are computed by comparing the old and new configuration. |
| * @param newConfiguration the new instance configuration |
| */ |
| public void reconfigure(Dictionary<String, Object> newConfiguration) { |
| // Copy the current configuration and update the field. |
| Hashtable<String, Object> configuration = new Hashtable<String, Object>(); |
| Enumeration<String> enumeration = m_configuration.keys(); |
| while (enumeration.hasMoreElements()) { |
| final String key = enumeration.nextElement(); |
| configuration.put(key, m_configuration.get(key)); |
| } |
| // We now have a copy of the current configuration. |
| // We must set the field to the new configuration, as updates are going to be fired. |
| // so we must have reflected the updates already. |
| m_configuration = newConfiguration; |
| |
| // We use the same loop to find lost and updated properties. |
| enumeration = configuration.keys(); |
| while (enumeration.hasMoreElements()) { |
| final String key = enumeration.nextElement(); |
| final Object newValue = newConfiguration.get(key); |
| final Object oldValue = configuration.get(key); |
| if (newValue == null) { |
| // If we don't have the property anymore, notify the departure. |
| fireUpdate(key, null); |
| } else { |
| // The new configuration still has a value, is it the same ? |
| if (! newValue.equals(oldValue)) { |
| fireUpdate(key, newValue); |
| } |
| } |
| } |
| |
| // Do we have new properties ? |
| enumeration = newConfiguration.keys(); |
| while (enumeration.hasMoreElements()) { |
| final String key = enumeration.nextElement(); |
| if (configuration.get(key) == null) { |
| Object newValue = newConfiguration.get(key); |
| fireUpdate(key, newValue); |
| } |
| } |
| } |
| |
| private void fireUpdate(String key, Object newValue) { |
| for (ContextListener listener : m_listeners) { |
| listener.update(this, key, newValue); |
| } |
| } |
| |
| public Object getProperty(String property) { |
| return m_configuration.get(property); |
| } |
| |
| public Dictionary getContext() { |
| return m_configuration; |
| } |
| |
| public void registerContextListener(ContextListener listener, String[] properties) { |
| if (! m_listeners.contains(listener)) { |
| m_listeners.add(listener); |
| } |
| } |
| |
| public void unregisterContextListener(ContextListener listener) { |
| m_listeners.remove(listener); |
| } |
| } |