org.springframework.remoting.rmi.RmiServiceExporter Maven / Gradle / Ivy
/*
* Copyright 2002-2004 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.lang.reflect.InvocationTargetException;
import java.rmi.NotBoundException;
import java.rmi.Remote;
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.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.remoting.support.RemoteInvocation;
import org.springframework.remoting.support.RemoteInvocationBasedExporter;
/**
* RMI exporter that exposes the specified service as RMI object with the specified
* name. Such services can be accessed via plain RMI or via RmiProxyFactoryBean.
* Also supports exposing any non-RMI service via RMI invokers, to be accessed via
* RmiClientInterceptor/RmiProxyFactoryBean's automatic detection of such invokers.
*
* With an RMI invoker, RMI communication works on the RmiInvocationHandler
* level, needing only one stub for any service. Service interfaces do not have to
* extend java.rmi.Remote or throw RemoteException on all methods, but in and out
* parameters have to be serializable.
*
*
The major advantage of RMI, compared to Hessian and Burlap, is serialization.
* Effectively, any serializable Java object can be transported without hassle.
* Hessian and Burlap have their own (de-)serialization mechanisms, but are
* HTTP-based and thus much easier to setup than RMI. Alternatively, consider
* Spring's HTTP invoker to combine Java serialization with HTTP-based transport.
*
*
Note: RMI makes a best-effort attempt to obtain the fully qualified host name.
* If one cannot be determined, it will fall back and use the IP address. Depending
* on your network configuration, in some cases it will resolve the IP to the loopback
* address. Ensuring that RMI will use the host name bound to the correct network
* interface you should pass the java.rmi.server.hostname property to the
* JVM that will export the registry and/or the service using the "-D" JVM argument.
* For example: -Djava.rmi.server.hostname=myserver.com
*
* @author Juergen Hoeller
* @since 13.05.2003
* @see RmiClientInterceptor
* @see RmiProxyFactoryBean
* @see java.rmi.Remote
* @see java.rmi.RemoteException
* @see org.springframework.remoting.caucho.HessianServiceExporter
* @see org.springframework.remoting.caucho.BurlapServiceExporter
* @see org.springframework.remoting.httpinvoker.HttpInvokerServiceExporter
*/
public class RmiServiceExporter extends RemoteInvocationBasedExporter
implements InitializingBean, DisposableBean {
private String registryHost;
private int registryPort = Registry.REGISTRY_PORT;
private String serviceName;
private int servicePort = 0; // anonymous port
private RMIClientSocketFactory clientSocketFactory;
private RMIServerSocketFactory serverSocketFactory;
private RMIClientSocketFactory registryClientSocketFactory;
private RMIServerSocketFactory registryServerSocketFactory;
private Remote exportedObject;
/**
* Set the port of the registry for the exported RMI service,
* i.e. rmi://HOST:port/name
*
Default is localhost.
*/
public void setRegistryHost(String registryHost) {
this.registryHost = registryHost;
}
/**
* Set the port of the registry for the exported RMI service,
* i.e. rmi://host:PORT/name
*
Default is Registry.REGISTRY_PORT (1099).
*/
public void setRegistryPort(int registryPort) {
this.registryPort = registryPort;
}
/**
* Set the name of the exported RMI service,
* i.e. rmi://host:port/NAME
*/
public void setServiceName(String serviceName) {
this.serviceName = serviceName;
}
/**
* Set the port that the exported RMI service will use.
*
Default is 0 (anonymous port).
*/
public void setServicePort(int servicePort) {
this.servicePort = servicePort;
}
/**
* Set a custom RMI client socket factory to use for exporting the service.
*
If the given object also implements 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 UnicastRemoteObject#exportObject(Remote, int, RMIClientSocketFactory, RMIServerSocketFactory)
*/
public void setClientSocketFactory(RMIClientSocketFactory clientSocketFactory) {
this.clientSocketFactory = clientSocketFactory;
}
/**
* Set a custom RMI server socket factory to use for exporting the service.
*
Only needs to be specified when the client socket factory does not
* implement java.rmi.server.RMIServerSocketFactory already.
* @see #setClientSocketFactory
* @see java.rmi.server.RMIClientSocketFactory
* @see java.rmi.server.RMIServerSocketFactory
* @see UnicastRemoteObject#exportObject(Remote, int, RMIClientSocketFactory, RMIServerSocketFactory)
*/
public void setServerSocketFactory(RMIServerSocketFactory serverSocketFactory) {
this.serverSocketFactory = serverSocketFactory;
}
/**
* Set a custom RMI client socket factory to use for the RMI registry.
*
If the given object also implements java.rmi.server.RMIServerSocketFactory,
* it will automatically be registered as server socket factory too.
* @see #setRegistryServerSocketFactory
* @see java.rmi.server.RMIClientSocketFactory
* @see java.rmi.server.RMIServerSocketFactory
* @see LocateRegistry#getRegistry(String, int, RMIClientSocketFactory)
*/
public void setRegistryClientSocketFactory(RMIClientSocketFactory registryClientSocketFactory) {
this.registryClientSocketFactory = registryClientSocketFactory;
}
/**
* 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 java.rmi.server.RMIServerSocketFactory already.
* @see #setRegistryClientSocketFactory
* @see java.rmi.server.RMIClientSocketFactory
* @see java.rmi.server.RMIServerSocketFactory
* @see LocateRegistry#createRegistry(int, RMIClientSocketFactory, RMIServerSocketFactory)
*/
public void setRegistryServerSocketFactory(RMIServerSocketFactory registryServerSocketFactory) {
this.registryServerSocketFactory = registryServerSocketFactory;
}
/**
* Register the service as RMI object.
* Creates an RMI registry on the specified port if none exists.
*/
public void afterPropertiesSet() throws RemoteException {
checkService();
if (this.serviceName == null) {
throw new IllegalArgumentException("serviceName is required");
}
// Check socket factories for exported object.
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");
}
// Check socket factories for RMI registry.
if (this.registryClientSocketFactory instanceof RMIServerSocketFactory) {
this.registryServerSocketFactory = (RMIServerSocketFactory) this.registryClientSocketFactory;
}
if (this.registryClientSocketFactory == null && this.registryServerSocketFactory != null) {
throw new IllegalArgumentException(
"RMIServerSocketFactory without RMIClientSocketFactory for registry not supported");
}
// Determine RMI registry to use.
Registry registry = getRegistry(this.registryHost, this.registryPort,
this.registryClientSocketFactory, this.registryServerSocketFactory);
// Initialize and cache exported object.
this.exportedObject = getObjectToExport();
// Export remote object and bind it to RMI registry.
if (logger.isInfoEnabled()) {
logger.info("Binding RMI service '" + this.serviceName +
"' to registry at port '" + this.registryPort + "'");
}
if (this.clientSocketFactory != null) {
UnicastRemoteObject.exportObject(
this.exportedObject, this.servicePort, this.clientSocketFactory, this.serverSocketFactory);
}
else {
UnicastRemoteObject.exportObject(this.exportedObject, this.servicePort);
}
registry.rebind(this.serviceName, this.exportedObject);
}
/**
* Locate or create the RMI registry for this exporter.
* @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 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 explictly specified: only lookup possible.
Registry registry = null;
if (clientSocketFactory != null) {
if (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "' of host [" + registryHost +
"], using custom socket factory");
}
registry = LocateRegistry.getRegistry(registryHost, registryPort, clientSocketFactory);
}
else {
if (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "' of host [" + registryHost + "]");
}
registry = LocateRegistry.getRegistry(registryHost, registryPort);
}
testRegistry(registry);
return registry;
}
else {
return getRegistry(registryPort, clientSocketFactory, serverSocketFactory);
}
}
/**
* Locate or create the RMI registry for this exporter.
* @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 (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "', using custom socket factory");
}
try {
// Retrieve existing registry.
Registry registry = LocateRegistry.getRegistry(null, registryPort, clientSocketFactory);
testRegistry(registry);
return registry;
}
catch (RemoteException ex) {
logger.debug("RMI registry access threw exception", ex);
logger.warn("Could not detect RMI registry - creating new one");
// Assume no registry found -> create new one.
return LocateRegistry.createRegistry(registryPort, clientSocketFactory, serverSocketFactory);
}
}
else {
return getRegistry(registryPort);
}
}
/**
* Locate or create the RMI registry for this exporter.
* @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 (logger.isInfoEnabled()) {
logger.info("Looking for RMI registry at port '" + registryPort + "'");
}
Registry registry;
try {
// Retrieve existing registry.
registry = LocateRegistry.getRegistry(registryPort);
testRegistry(registry);
}
catch (RemoteException ex) {
logger.debug("RMI registry access threw exception", ex);
logger.warn("Could not detect RMI registry - creating new one");
// Assume no registry found -> create new one.
registry = LocateRegistry.createRegistry(registryPort);
}
return registry;
}
/**
* Test the given RMI registry, calling some operation on it to
* check whether it is still active.
* @param registry the RMI registry to test
* @throws RemoteException if thrown by registry methods
*/
protected void testRegistry(Registry registry) throws RemoteException {
registry.list();
}
/**
* Determine the object to export: either the service object itself
* or a RmiInvocationWrapper in case of a non-RMI service object.
* @return the RMI object to export
*/
protected Remote getObjectToExport() {
// determine remote object
if (getService() instanceof Remote &&
((getServiceInterface() == null) || Remote.class.isAssignableFrom(getServiceInterface()))) {
// conventional RMI service
return (Remote) getService();
}
else {
// RMI invoker
if (logger.isInfoEnabled()) {
logger.info("RMI object '" + this.serviceName + "' is an RMI invoker");
}
return new RmiInvocationWrapper(getProxyForService(), this);
}
}
/**
* Redefined here to be visible to RmiInvocationWrapper.
* Simply delegates to the corresponding superclass method.
*/
protected Object invoke(RemoteInvocation invocation, Object targetObject)
throws NoSuchMethodException, IllegalAccessException, InvocationTargetException{
return super.invoke(invocation, targetObject);
}
/**
* Unbind the RMI service from the registry at bean factory shutdown.
*/
public void destroy() throws RemoteException, NotBoundException {
if (logger.isInfoEnabled()) {
logger.info("Unbinding RMI service '" + this.serviceName +
"' from registry at port '" + this.registryPort + "'");
}
Registry registry = LocateRegistry.getRegistry(
this.registryHost, this.registryPort, this.registryClientSocketFactory);
registry.unbind(this.serviceName);
UnicastRemoteObject.unexportObject(this.exportedObject, true);
}
}