1 /*
2 * Copyright 2002-2007 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.support;
18
19 import java.lang.reflect.InvocationTargetException;
20
21 /**
22 * Abstract base class for remote service exporters that are based
23 * on deserialization of {@link RemoteInvocation} objects.
24 *
25 * <p>Provides a "remoteInvocationExecutor" property, with a
26 * {@link DefaultRemoteInvocationExecutor} as default strategy.
27 *
28 * @author Juergen Hoeller
29 * @since 1.1
30 * @see RemoteInvocationExecutor
31 * @see DefaultRemoteInvocationExecutor
32 */
33 public abstract class RemoteInvocationBasedExporter extends RemoteExporter {
34
35 private RemoteInvocationExecutor remoteInvocationExecutor = new DefaultRemoteInvocationExecutor();
36
37
38 /**
39 * Set the RemoteInvocationExecutor to use for this exporter.
40 * Default is a DefaultRemoteInvocationExecutor.
41 * <p>A custom invocation executor can extract further context information
42 * from the invocation, for example user credentials.
43 */
44 public void setRemoteInvocationExecutor(RemoteInvocationExecutor remoteInvocationExecutor) {
45 this.remoteInvocationExecutor = remoteInvocationExecutor;
46 }
47
48 /**
49 * Return the RemoteInvocationExecutor used by this exporter.
50 */
51 public RemoteInvocationExecutor getRemoteInvocationExecutor() {
52 return this.remoteInvocationExecutor;
53 }
54
55
56 /**
57 * Apply the given remote invocation to the given target object.
58 * The default implementation delegates to the RemoteInvocationExecutor.
59 * <p>Can be overridden in subclasses for custom invocation behavior,
60 * possibly for applying additional invocation parameters from a
61 * custom RemoteInvocation subclass. Note that it is preferable to use
62 * a custom RemoteInvocationExecutor which is a reusable strategy.
63 * @param invocation the remote invocation
64 * @param targetObject the target object to apply the invocation to
65 * @return the invocation result
66 * @throws NoSuchMethodException if the method name could not be resolved
67 * @throws IllegalAccessException if the method could not be accessed
68 * @throws InvocationTargetException if the method invocation resulted in an exception
69 * @see RemoteInvocationExecutor#invoke
70 */
71 protected Object invoke(RemoteInvocation invocation, Object targetObject)
72 throws NoSuchMethodException, IllegalAccessException, InvocationTargetException {
73
74 if (logger.isTraceEnabled()) {
75 logger.trace("Executing " + invocation);
76 }
77 try {
78 return getRemoteInvocationExecutor().invoke(invocation, targetObject);
79 }
80 catch (NoSuchMethodException ex) {
81 if (logger.isDebugEnabled()) {
82 logger.warn("Could not find target method for " + invocation, ex);
83 }
84 throw ex;
85 }
86 catch (IllegalAccessException ex) {
87 if (logger.isDebugEnabled()) {
88 logger.warn("Could not access target method for " + invocation, ex);
89 }
90 throw ex;
91 }
92 catch (InvocationTargetException ex) {
93 if (logger.isDebugEnabled()) {
94 logger.debug("Target method failed for " + invocation, ex.getTargetException());
95 }
96 throw ex;
97 }
98 }
99
100 /**
101 * Apply the given remote invocation to the given target object, wrapping
102 * the invocation result in a serializable RemoteInvocationResult object.
103 * The default implementation creates a plain RemoteInvocationResult.
104 * <p>Can be overridden in subclasses for custom invocation behavior,
105 * for example to return additional context information. Note that this
106 * is not covered by the RemoteInvocationExecutor strategy!
107 * @param invocation the remote invocation
108 * @param targetObject the target object to apply the invocation to
109 * @return the invocation result
110 * @see #invoke
111 */
112 protected RemoteInvocationResult invokeAndCreateResult(RemoteInvocation invocation, Object targetObject) {
113 try {
114 Object value = invoke(invocation, targetObject);
115 return new RemoteInvocationResult(value);
116 }
117 catch (Throwable ex) {
118 return new RemoteInvocationResult(ex);
119 }
120 }
121
122 }