Spring Framework example source code file (ThrowsAdviceInterceptor.java)

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Java - Spring Framework tags/keywords

afteradvice, found, found, hashmap, illegalargumentexception, map, method, method, object, object, reflection, string, throwable, throwable, throwsadviceinterceptor, util

The Spring Framework ThrowsAdviceInterceptor.java source code

/*
 * Copyright 2002-2007 the original author or authors.
 *
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-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.springframework.aop.framework.adapter;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.aop.AfterAdvice;
import org.springframework.util.Assert;

/**
 * Interceptor to wrap an after-throwing advice.
 *
 * <p>The signatures on handler methods on the ThrowsAdvice
 * implementation method argument must be of the form:<br>
 *
 * <code>void afterThrowing([Method, args, target], ThrowableSubclass);
 *
 * <p>Only the last argument is required.
 *
 * <p>Some examples of valid methods would be:
 *
 * <pre class="code">public void afterThrowing(Exception ex)

* <pre class="code">public void afterThrowing(RemoteException) * <pre class="code">public void afterThrowing(Method method, Object[] args, Object target, Exception ex) * <pre class="code">public void afterThrowing(Method method, Object[] args, Object target, ServletException ex) * * <p>This is a framework class that need not be used directly by Spring users. * * @author Rod Johnson * @author Juergen Hoeller */ public class ThrowsAdviceInterceptor implements MethodInterceptor, AfterAdvice { private static final String AFTER_THROWING = "afterThrowing"; private static final Log logger = LogFactory.getLog(ThrowsAdviceInterceptor.class); private final Object throwsAdvice; /** Methods on throws advice, keyed by exception class */ private final Map exceptionHandlerMap = new HashMap(); /** * Create a new ThrowsAdviceInterceptor for the given ThrowsAdvice. * @param throwsAdvice the advice object that defines the exception * handler methods (usually a {@link org.springframework.aop.ThrowsAdvice} * implementation) */ public ThrowsAdviceInterceptor(Object throwsAdvice) { Assert.notNull(throwsAdvice, "Advice must not be null"); this.throwsAdvice = throwsAdvice; Method[] methods = throwsAdvice.getClass().getMethods(); for (int i = 0; i < methods.length; i++) { Method method = methods[i]; if (method.getName().equals(AFTER_THROWING) && //m.getReturnType() == null && (method.getParameterTypes().length == 1 || method.getParameterTypes().length == 4) && Throwable.class.isAssignableFrom(method.getParameterTypes()[method.getParameterTypes().length - 1]) ) { // Have an exception handler this.exceptionHandlerMap.put(method.getParameterTypes()[method.getParameterTypes().length - 1], method); if (logger.isDebugEnabled()) { logger.debug("Found exception handler method: " + method); } } } if (this.exceptionHandlerMap.isEmpty()) { throw new IllegalArgumentException( "At least one handler method must be found in class [" + throwsAdvice.getClass() + "]"); } } public int getHandlerMethodCount() { return this.exceptionHandlerMap.size(); } /** * Determine the exception handle method. Can return null if not found. * @param exception the exception thrown * @return a handler for the given exception type */ private Method getExceptionHandler(Throwable exception) { Class exceptionClass = exception.getClass(); if (logger.isTraceEnabled()) { logger.trace("Trying to find handler for exception of type [" + exceptionClass.getName() + "]"); } Method handler = (Method) this.exceptionHandlerMap.get(exceptionClass); while (handler == null && !exceptionClass.equals(Throwable.class)) { exceptionClass = exceptionClass.getSuperclass(); handler = (Method) this.exceptionHandlerMap.get(exceptionClass); } if (handler != null && logger.isDebugEnabled()) { logger.debug("Found handler for exception of type [" + exceptionClass.getName() + "]: " + handler); } return handler; } public Object invoke(MethodInvocation mi) throws Throwable { try { return mi.proceed(); } catch (Throwable ex) { Method handlerMethod = getExceptionHandler(ex); if (handlerMethod != null) { invokeHandlerMethod(mi, ex, handlerMethod); } throw ex; } } private void invokeHandlerMethod(MethodInvocation mi, Throwable ex, Method method) throws Throwable { Object[] handlerArgs; if (method.getParameterTypes().length == 1) { handlerArgs = new Object[] { ex }; } else { handlerArgs = new Object[] {mi.getMethod(), mi.getArguments(), mi.getThis(), ex}; } try { method.invoke(this.throwsAdvice, handlerArgs); } catch (InvocationTargetException targetEx) { throw targetEx.getTargetException(); } } }