1 /*
2 * Copyright 2002-2008 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.remoting.rmi;
18
19 import java.lang.reflect.InvocationTargetException;
20 import java.rmi.Remote;
21
22 import org.springframework.remoting.support.RemoteInvocation;
23 import org.springframework.remoting.support.RemoteInvocationBasedExporter;
24
25 /**
26 * Convenient superclass for RMI-based remote exporters. Provides a facility
27 * to automatically wrap a given plain Java service object with an
28 * RmiInvocationWrapper, exposing the {@link RmiInvocationHandler} remote interface.
29 *
30 * <p>Using the RMI invoker mechanism, RMI communication operates at the {@link RmiInvocationHandler}
31 * level, sharing a common invoker stub for any number of services. Service interfaces are <i>not</i>
32 * required to extend <code>java.rmi.Remote</code> or declare <code>java.rmi.RemoteException</code>
33 * on all service methods. However, in and out parameters still have to be serializable.
34 *
35 * @author Juergen Hoeller
36 * @since 1.2.5
37 * @see RmiServiceExporter
38 * @see JndiRmiServiceExporter
39 */
40 public abstract class RmiBasedExporter extends RemoteInvocationBasedExporter {
41
42 /**
43 * Determine the object to export: either the service object itself
44 * or a RmiInvocationWrapper in case of a non-RMI service object.
45 * @return the RMI object to export
46 * @see #setService
47 * @see #setServiceInterface
48 */
49 protected Remote getObjectToExport() {
50 // determine remote object
51 if (getService() instanceof Remote &&
52 (getServiceInterface() == null || Remote.class.isAssignableFrom(getServiceInterface()))) {
53 // conventional RMI service
54 return (Remote) getService();
55 }
56 else {
57 // RMI invoker
58 if (logger.isDebugEnabled()) {
59 logger.debug("RMI service [" + getService() + "] is an RMI invoker");
60 }
61 return new RmiInvocationWrapper(getProxyForService(), this);
62 }
63 }
64
65 /**
66 * Redefined here to be visible to RmiInvocationWrapper.
67 * Simply delegates to the corresponding superclass method.
68 */
69 protected Object invoke(RemoteInvocation invocation, Object targetObject)
70 throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
71
72 return super.invoke(invocation, targetObject);
73 }
74
75 }
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