/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community 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.osedu.org/licenses/ECL-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.kuali.student.common.util;

 import java.io.PrintWriter;

 import java.io.StringWriter;

 import java.lang.reflect.Constructor;

 import java.util.Map;

 import org.apache.log4j.Logger;

 import org.springframework.aop.ThrowsAdvice;

 import org.springframework.core.Ordered;

 /**

  * @author Daniel Epstein

  *         <p>

  *         Use this Advice to map one exception to another for use when other

  *         advice eats your runtime exceptions outside of your code. This happens in

  *         Transactions when commit is not called until outside of your DAO

  *         layer.

  *         </p>

  * 

  * <p>

  * Set the property "exceptionMapping" as a map that maps an exception class to

  * your own exception class

  * </p>

  * 

  * <p>

  * Remember that aspect order is important and that this bean will always be

  * order "500"

  * </p>

  * 

  * Example:

  * 

  * <pre>

  * <tx:annotation-driven transaction-manager="JtaTxManager" order="1000"/>

  * lt;bean id="mapExceptionAdvisor"

  * class="org.myfoo.ExceptionMappingAdvice">

  * <property name="exceptionMapping">

  *         <map>

  *                 <entry key="javax.persistence.EntityExistsException"

  *                         value="org.myfoo.exceptions.AlreadyExistsException" />

  *         </map>

  * </property>

  * lt;/bean>

  * lt;aop:config>

  * <aop:aspect id="dataAccessToBusinessException"

  *         ref="mapExceptionAdvisor">

  *         <aop:after-throwing

  *                 pointcut="execution(* org.myfoo.service.*.*(..))"

  *                 method="afterThrowing" throwing="ex" />

  * </aop:aspect>

  * lt;/aop:config>

  * </pre>

  */

 public class ExceptionMappingAdvice implements ThrowsAdvice, Ordered {

         private int order = 500;

         private static final long serialVersionUID = 1L;

         private Map<Class<? extends Exception>, Class<? extends Exception>> exceptionMapping;

         private Class<? extends Exception> defaultException;

         final Logger logger = Logger.getLogger(ExceptionMappingAdvice.class);

         /**

          * This method will use the real exception thrown and look up the exception

          * that should be thrown

          * 

          * @param ex

          * @throws Exception

          */

         public void afterThrowing(Exception ex) throws Exception {

                 Class<? extends Exception> mappedExceptionClass = exceptionMapping

                                 .get(ex.getClass());

                 if (mappedExceptionClass != null) {

                 logger.debug("Mapping exception "+ex.getClass()+" to "+mappedExceptionClass);

                 Constructor<? extends Exception> c = mappedExceptionClass

                                         .getConstructor(String.class);

                         Exception mappedException = c.newInstance(ex.getMessage());

                         throw mappedException;

                 }

                 //Throw a default exception if this is a runtime exception

                 if(ex instanceof RuntimeException){

                         logger.trace("No mapping available, throwing default exception "+defaultException);

                         if (defaultException != null) {

                                 //Log the error

                                 StringWriter traceWriter = new StringWriter();

                                 PrintWriter printWriter = new PrintWriter(traceWriter, false);

                                 logger.error(printWriter, ex);

                                 printWriter.close();

                                 String faultMessage = traceWriter.getBuffer().toString();

                                 logger.error(faultMessage);

                                 //Throw the default exception

                                 try{

                                         Constructor<? extends Exception> c = defaultException

                                                         .getConstructor(String.class, Throwable.class);

                                         throw c.newInstance(ex.getMessage(), ex);

                                 }catch(NoSuchMethodException e){

                                         Constructor<? extends Exception> c = defaultException

                                                         .getConstructor(String.class);

                                         throw c.newInstance(ex.getMessage());

                                 }

                         }

                         //Check if no default was defined

                         logger.debug("No mapping or default exception available. Exception "+ex.getClass());

                         throw new RuntimeException("Could Not Map Exception: " + ex.toString());

                 }

         }

         @Override

         public int getOrder() {

                 return order;

         }

         /**

          * @param order

          *            the order to set

          */

         public void setOrder(int order) {

                 this.order = order;

         }

         /**

          * @return the exceptionMapping

          */

         public Map<Class<? extends Exception>, Class<? extends Exception>> getExceptionMapping() {

                 return exceptionMapping;

         }

         /**

          * @param exceptionMapping

          *            the exceptionMapping to set

          */

         public void setExceptionMapping(

                         Map<Class<? extends Exception>, Class<? extends Exception>> exceptionMapping) {

                 this.exceptionMapping = exceptionMapping;

         }

         /**

          * @return the defaultException

          */

         public Class<? extends Exception> getDefaultException() {

                 return defaultException;

         }

         /**

          * @param defaultException

          *            the defaultException to set

          */

         public void setDefaultException(Class<? extends Exception> defaultException) {

                 this.defaultException = defaultException;

         }

 }