/**
* 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.synapse.commons.util;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.commons.SynapseCommonsException;
import java.rmi.NoSuchObjectException;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
/**
* Creates and manages RMI registries
*/
public class RMIRegistryController {
public static final Log log = LogFactory.getLog(RMIRegistryController.class);
private static RMIRegistryController ourInstance = new RMIRegistryController();
private final Map<String, Registry> registriesCache = new HashMap<String, Registry>();
public static RMIRegistryController getInstance() {
return ourInstance;
}
private RMIRegistryController() {
}
/**
* Creates a RMI local registry with given port
*
* @param port The port of the RMI registry to be created
*/
public void createLocalRegistry(int port) {
try {
String key = toKey(port);
synchronized (registriesCache) {
if (registriesCache.containsKey(key)) {
if (log.isDebugEnabled()) {
log.debug("There is an RMI registry bound to given port :" + port);
}
return;
}
Registry locateRegistry = LocateRegistry.createRegistry(port);
if (locateRegistry == null) {
handleException("Unable to create a RMI registry with port : " + port);
}
registriesCache.put(key, locateRegistry);
}
} catch (RemoteException e) {
String msg = "Couldn't create a local registry(RMI) : port " + port +
" already in use.";
handleException(msg, e);
}
}
/**
* removes if there is a RMI local registry instance
*
* @param port The port of the RMI registry to be removed
*/
public void removeLocalRegistry(int port) {
String key = toKey(port);
synchronized (registriesCache) {
if (registriesCache.containsKey(key)) {
removeRegistry(key, registriesCache.get(key));
} else {
if (log.isDebugEnabled()) {
log.debug("There is no RMi registry for port : " + port);
}
}
}
}
/**
* Removes all registered RMI registries
*/
public void shutDown() {
synchronized (registriesCache) {
Collection<String> registryKeys = new ArrayList<String>(registriesCache.size());
registryKeys.addAll(registriesCache.keySet());
for (String key : registryKeys) {
removeRegistry(key, registriesCache.get(key));
}
}
}
/**
* Helper method to remove a RMI registry instance
*
* @param key The port of the RMI registry to be removed
* @param registry Registry instance
*/
private void removeRegistry(String key, Registry registry) {
if (registry != null) {
synchronized (registriesCache) {
try {
log.info("Removing the RMI registry bound to port : " + key);
UnicastRemoteObject.unexportObject(registry, true);
registriesCache.remove(key);
} catch (NoSuchObjectException e) {
String msg = "Error when stopping local registry(RMI)";
handleException(msg, e);
}
}
}
}
private static String toKey(int port) {
assertPositive(port);
return String.valueOf(port);
}
private static void assertPositive(int port) {
if (port < 0) {
handleException("Invalid port number : " + port);
}
}
/**
* Helper methods for handle errors.
*
* @param msg The error message
* @param e The exception
*/
private static void handleException(String msg, Exception e) {
log.error(msg, e);
throw new SynapseCommonsException(msg, e);
}
/**
* Helper methods for handle errors.
*
* @param msg The error message
*/
private static void handleException(String msg) {
log.error(msg);
throw new SynapseCommonsException(msg);
}
}