org.springframework.remoting.rmi.RmiRegistryFactoryBean Maven / Gradle / Ivy
/*
* Copyright 2002-2013 the original author or authors.
*
* Licensed 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.springframework.remoting.rmi;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.server.RMIServerSocketFactory;
import java.rmi.server.UnicastRemoteObject;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
/**
* {@link FactoryBean} that locates a {@link java.rmi.registry.Registry} and
* exposes it for bean references. Can also create a local RMI registry
* on the fly if none exists already.
*
* Can be used to set up and pass around the actual Registry object to
* applications objects that need to work with RMI. One example for such an
* object that needs to work with RMI is Spring's {@link RmiServiceExporter},
* which either works with a passed-in Registry reference or falls back to
* the registry as specified by its local properties and defaults.
*
*
Also useful to enforce creation of a local RMI registry at a given port,
* for example for a JMX connector. If used in conjunction with
* {@link org.springframework.jmx.support.ConnectorServerFactoryBean},
* it is recommended to mark the connector definition (ConnectorServerFactoryBean)
* as "depends-on" the registry definition (RmiRegistryFactoryBean),
* to guarantee starting up the registry first.
*
*
Note: The implementation of this class mirrors the corresponding logic
* in {@link RmiServiceExporter}, and also offers the same customization hooks.
* RmiServiceExporter implements its own registry lookup as a convenience:
* It is very common to simply rely on the registry defaults.
*
* @author Juergen Hoeller
* @since 1.2.3
* @see RmiServiceExporter#setRegistry
* @see org.springframework.jmx.support.ConnectorServerFactoryBean
* @see java.rmi.registry.Registry
* @see java.rmi.registry.LocateRegistry
*/
public class RmiRegistryFactoryBean implements FactoryBean, InitializingBean, DisposableBean {
protected final Log logger = LogFactory.getLog(getClass());
private String host;
private int port = Registry.REGISTRY_PORT;
private RMIClientSocketFactory clientSocketFactory;
private RMIServerSocketFactory serverSocketFactory;
private Registry registry;
private boolean alwaysCreate = false;
private boolean created = false;
/**
* Set the host of the registry for the exported RMI service,
* i.e. {@code rmi://HOST:port/name}
* Default is localhost.
*/
public void setHost(String host) {
this.host = host;
}
/**
* Return the host of the registry for the exported RMI service.
*/
public String getHost() {
return this.host;
}
/**
* Set the port of the registry for the exported RMI service,
* i.e. {@code rmi://host:PORT/name}
*
Default is {@code Registry.REGISTRY_PORT} (1099).
*/
public void setPort(int port) {
this.port = port;
}
/**
* Return the port of the registry for the exported RMI service.
*/
public int getPort() {
return this.port;
}
/**
* Set a custom RMI client socket factory to use for the RMI registry.
*
If the given object also implements {@code java.rmi.server.RMIServerSocketFactory},
* it will automatically be registered as server socket factory too.
* @see #setServerSocketFactory
* @see java.rmi.server.RMIClientSocketFactory
* @see java.rmi.server.RMIServerSocketFactory
* @see java.rmi.registry.LocateRegistry#getRegistry(String, int, java.rmi.server.RMIClientSocketFactory)
*/
public void setClientSocketFactory(RMIClientSocketFactory clientSocketFactory) {
this.clientSocketFactory = clientSocketFactory;
}
/**
* Set a custom RMI server socket factory to use for the RMI registry.
*
Only needs to be specified when the client socket factory does not
* implement {@code java.rmi.server.RMIServerSocketFactory} already.
* @see #setClientSocketFactory
* @see java.rmi.server.RMIClientSocketFactory
* @see java.rmi.server.RMIServerSocketFactory
* @see java.rmi.registry.LocateRegistry#createRegistry(int, RMIClientSocketFactory, java.rmi.server.RMIServerSocketFactory)
*/
public void setServerSocketFactory(RMIServerSocketFactory serverSocketFactory) {
this.serverSocketFactory = serverSocketFactory;
}
/**
* Set whether to always create the registry in-process,
* not attempting to locate an existing registry at the specified port.
*
Default is "false". Switch this flag to "true" in order to avoid
* the overhead of locating an existing registry when you always
* intend to create a new registry in any case.
*/
public void setAlwaysCreate(boolean alwaysCreate) {
this.alwaysCreate = alwaysCreate;
}
@Override
public void afterPropertiesSet() throws Exception {
// Check socket factories for registry.
if (this.clientSocketFactory instanceof RMIServerSocketFactory) {
this.serverSocketFactory = (RMIServerSocketFactory) this.clientSocketFactory;
}
if ((this.clientSocketFactory != null && this.serverSocketFactory == null) ||
(this.clientSocketFactory == null && this.serverSocketFactory != null)) {
throw new IllegalArgumentException(
"Both RMIClientSocketFactory and RMIServerSocketFactory or none required");
}
// Fetch RMI registry to expose.
this.registry = getRegistry(this.host, this.port, this.clientSocketFactory, this.serverSocketFactory);
}
/**
* Locate or create the RMI registry.
* @param registryHost the registry host to use (if this is specified,
* no implicit creation of a RMI registry will happen)
* @param registryPort the registry port to use
* @param clientSocketFactory the RMI client socket factory for the registry (if any)
* @param serverSocketFactory the RMI server socket factory for the registry (if any)
* @return the RMI registry
* @throws java.rmi.RemoteException if the registry couldn't be located or created
*/
protected Registry getRegistry(String registryHost, int registryPort,
RMIClientSocketFactory clientSocketFactory, RMIServerSocketFactory serverSocketFactory)
throws RemoteException {
if (registryHost != null) {
// Host explicitly specified: only lookup possible.
if (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "' of host [" + registryHost + "]");
}
Registry reg = LocateRegistry.getRegistry(registryHost, registryPort, clientSocketFactory);
testRegistry(reg);
return reg;
}
else {
return getRegistry(registryPort, clientSocketFactory, serverSocketFactory);
}
}
/**
* Locate or create the RMI registry.
* @param registryPort the registry port to use
* @param clientSocketFactory the RMI client socket factory for the registry (if any)
* @param serverSocketFactory the RMI server socket factory for the registry (if any)
* @return the RMI registry
* @throws RemoteException if the registry couldn't be located or created
*/
protected Registry getRegistry(
int registryPort, RMIClientSocketFactory clientSocketFactory, RMIServerSocketFactory serverSocketFactory)
throws RemoteException {
if (clientSocketFactory != null) {
if (this.alwaysCreate) {
logger.info("Creating new RMI registry");
this.created = true;
return LocateRegistry.createRegistry(registryPort, clientSocketFactory, serverSocketFactory);
}
if (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "', using custom socket factory");
}
synchronized (LocateRegistry.class) {
try {
// Retrieve existing registry.
Registry reg = LocateRegistry.getRegistry(null, registryPort, clientSocketFactory);
testRegistry(reg);
return reg;
}
catch (RemoteException ex) {
logger.debug("RMI registry access threw exception", ex);
logger.info("Could not detect RMI registry - creating new one");
// Assume no registry found -> create new one.
this.created = true;
return LocateRegistry.createRegistry(registryPort, clientSocketFactory, serverSocketFactory);
}
}
}
else {
return getRegistry(registryPort);
}
}
/**
* Locate or create the RMI registry.
* @param registryPort the registry port to use
* @return the RMI registry
* @throws RemoteException if the registry couldn't be located or created
*/
protected Registry getRegistry(int registryPort) throws RemoteException {
if (this.alwaysCreate) {
logger.info("Creating new RMI registry");
this.created = true;
return LocateRegistry.createRegistry(registryPort);
}
if (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "'");
}
synchronized (LocateRegistry.class) {
try {
// Retrieve existing registry.
Registry reg = LocateRegistry.getRegistry(registryPort);
testRegistry(reg);
return reg;
}
catch (RemoteException ex) {
logger.debug("RMI registry access threw exception", ex);
logger.info("Could not detect RMI registry - creating new one");
// Assume no registry found -> create new one.
this.created = true;
return LocateRegistry.createRegistry(registryPort);
}
}
}
/**
* Test the given RMI registry, calling some operation on it to
* check whether it is still active.
*
Default implementation calls {@code Registry.list()}.
* @param registry the RMI registry to test
* @throws RemoteException if thrown by registry methods
* @see java.rmi.registry.Registry#list()
*/
protected void testRegistry(Registry registry) throws RemoteException {
registry.list();
}
@Override
public Registry getObject() throws Exception {
return this.registry;
}
@Override
public Class getObjectType() {
return (this.registry != null ? this.registry.getClass() : Registry.class);
}
@Override
public boolean isSingleton() {
return true;
}
/**
* Unexport the RMI registry on bean factory shutdown,
* provided that this bean actually created a registry.
*/
@Override
public void destroy() throws RemoteException {
if (this.created) {
logger.info("Unexporting RMI registry");
UnicastRemoteObject.unexportObject(this.registry, true);
}
}
}