1 /*
2 * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
3 * the spring framework, http://el4j.sf.net
4 * Copyright (C) 2005 by ELCA Informatique SA, Av. de la Harpe 22-24,
5 * 1000 Lausanne, Switzerland, http://www.elca.ch
6 *
7 * EL4J is published under the GNU Lesser General Public License (LGPL)
8 * Version 2.1. See http://www.gnu.org/licenses/
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU Lesser General Public License for more details.
14 *
15 * For alternative licensing, please contact info@elca.ch
16 */
17
18 package ch.elca.el4j.services.exceptionhandler.handler;
19
20 import org.aopalliance.intercept.MethodInvocation;
21 import org.slf4j.Logger;
22
23 import ch.elca.el4j.services.exceptionhandler.AbstractExceptionHandlerInterceptor;
24
25 /**
26 * This is a convenience abstract class to create exception transformer
27 * exception handlers.
28 *
29 * @svnLink $Revision: 3873 $;$Date: 2009-08-04 13:59:45 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/exception_handling/src/main/java/ch/elca/el4j/services/exceptionhandler/handler/AbstractExceptionTransformerExceptionHandler.java $
30 *
31 * @author Andreas Bur (ABU)
32 */
33 public abstract class AbstractExceptionTransformerExceptionHandler extends
34 AbstractExceptionHandler {
35
36 /**
37 * {@inheritDoc}
38 */
39 protected Object handleException(Throwable t,
40 AbstractExceptionHandlerInterceptor exceptionInvoker,
41 MethodInvocation invocation, Logger logger) throws Throwable {
42
43 Exception transformed = transform(t, logger);
44 if (transformed == null) {
45 return null;
46 } else {
47 throw transformed;
48 }
49 }
50
51 /**
52 * Transforms the given throwable into an appropriate exception.
53 *
54 * @param t
55 * The throwable to transform.
56 *
57 * @param logger
58 * The logger that is configured properly.
59 *
60 * @return Returns the transformed exception or <code>null</code> if no
61 * exceptions has to be thrown.
62 */
63 protected abstract Exception transform(Throwable t, Logger logger);
64 }