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Java > Open Source Codes > org > apache > geronimo > core > service > InvocationResult


1 /**
2  *
3  * Copyright 2003-2004 The Apache Software Foundation
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */

17
18 package org.apache.geronimo.core.service;
19
20 /**
21  * The result of an Invocation.
22  * There are two types of result:
23  * <ul>
24  * <li>normal - indicating the operation completed normally (e.g. the method returned)</li>
25  * <li>exception - indicating the operation completed abnormally (e.g. the method threw a checked exception)</li>
26  * </ul>
27  * <p>Note that these should both be considered a normal completion of the operation by the container. Abnormal
28  * completions, such as a RuntimeException or Error from the invocation, or any problem in the interceptor
29  * chain itself, should result in a Throwable being thrown up the chain rather than being contained in this
30  * result.</p>
31  * <p>This distinction mirrors the semantics for EJB invocations, where a business method is considered to have
32  * completed successfuly even if it throws declared Exception - the Exception there is indicating a business level
33  * issue and not a system problem.</p>
34  *
35  * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
36  */

37 public interface InvocationResult {
38     /**
39      * Was this a normal completion (return)?
40      * @return true if the invocation returned; false if a declared exception was thrown
41      */

42     boolean isNormal();
43
44     /**
45      * Get the return value from the invocation.
46      * It is an error to call this method if the invocation is not complete normally.
47      * @return the return value from the invocation; null if the operation was void
48      */

49     Object JavaDoc getResult();
50
51     /**
52      * Was an application exception raised by the invocation?
53      * Note, this indicates a checked application exception was thrown; this will never contain
54      * a system exception
55      * @return true if a declared exception was thrown; false if the invocation returned
56      */

57     boolean isException();
58
59     /**
60      * Get the application exception raised by the invocation.
61      * It is an error to call this method if the invocation did not raise an exception
62      * @return the checked Exception raised by the application
63      */

64     Exception JavaDoc getException();
65 }
66
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