1 /* 2 * $Id$ 3 * 4 * Licensed to the Apache Software Foundation (ASF) under one 5 * or more contributor license agreements. See the NOTICE file 6 * distributed with this work for additional information 7 * regarding copyright ownership. The ASF licenses this file 8 * to you under the Apache License, Version 2.0 (the 9 * "License"); you may not use this file except in compliance 10 * with the License. You may obtain a copy of the License at 11 * 12 * http://www.apache.org/licenses/LICENSE-2.0 13 * 14 * Unless required by applicable law or agreed to in writing, 15 * software distributed under the License is distributed on an 16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 17 * KIND, either express or implied. See the License for the 18 * specific language governing permissions and limitations 19 * under the License. 20 */ 21 package org.apache.struts.chain.commands; 22 23 import org.apache.struts.chain.contexts.ActionContext; 24 import org.apache.struts.config.ActionConfig; 25 import org.apache.struts.config.ExceptionConfig; 26 import org.apache.struts.config.ForwardConfig; 27 import org.apache.struts.config.ModuleConfig; 28 import org.slf4j.Logger; 29 import org.slf4j.LoggerFactory; 30 31 /** 32 * <p>Invoke the local or global exception handler configured for the 33 * exception class that occurred.</p> 34 * 35 * @version $Rev$ $Date: 2005-11-12 13:01:44 -0500 (Sat, 12 Nov 2005) 36 * $ 37 */ 38 public abstract class AbstractExceptionHandler extends ActionCommandBase { 39 // ------------------------------------------------------ Instance Variables 40 41 /** 42 * The {@code Log} instance for this class. 43 */ 44 private final Logger log = 45 LoggerFactory.getLogger(AbstractExceptionHandler.class); 46 47 // ---------------------------------------------------------- Public Methods 48 49 /** 50 * <p>Invoke the appropriate <code>Action</code> for this request, and 51 * cache the returned <code>ActionForward</code>.</p> 52 * 53 * @param actionCtx The <code>Context</code> for the current request 54 * @return <code>false</code> if a <code>ForwardConfig</code> is returned, 55 * else <code>true</code> to complete processing 56 * @throws Exception if thrown by the Action class and not declared by an 57 * Exception Handler 58 */ 59 @Override 60 protected boolean execute_(ActionContext actionCtx) 61 throws Exception { 62 // Look up the exception that was thrown 63 Exception exception = actionCtx.getException(); 64 65 if (exception == null) { 66 log.warn("No Exception found in ActionContext"); 67 68 return PROCESSING_COMPLETE; 69 } 70 71 // Look up the local or global exception handler configuration 72 ExceptionConfig exceptionConfig = null; 73 ActionConfig actionConfig = actionCtx.getActionConfig(); 74 ModuleConfig moduleConfig = actionCtx.getModuleConfig(); 75 76 if (actionConfig != null) { 77 log.debug("See if actionConfig {} has an exceptionConfig for {}", 78 actionConfig, exception.getClass().getName()); 79 80 exceptionConfig = actionConfig.findException(exception.getClass()); 81 } else if (moduleConfig != null) { 82 log.debug("No action yet, see if moduleConfig {} has an exceptionConfig {}", 83 moduleConfig, exception.getClass().getName()); 84 85 exceptionConfig = moduleConfig.findException(exception.getClass()); 86 } 87 88 // Handle the exception in the configured manner 89 if (exceptionConfig == null) { 90 log.warn("Unhandled exception", exception); 91 throw exception; 92 } 93 94 ForwardConfig forwardConfig = 95 handle(actionCtx, exception, exceptionConfig, actionConfig, 96 moduleConfig); 97 98 if (forwardConfig != null) { 99 actionCtx.setForwardConfig(forwardConfig); 100 101 return CONTINUE_PROCESSING; 102 } else { 103 return PROCESSING_COMPLETE; 104 } 105 } 106 107 // ------------------------------------------------------- Protected Methods 108 109 /** 110 * <p>Perform the required handling of the specified exception.</p> 111 * 112 * @param context The <code>Context</code> for this request 113 * @param exception The exception being handled 114 * @param exceptionConfig The corresponding {@link ExceptionConfig} 115 * @param actionConfig The {@link ActionConfig} for this request 116 * @param moduleConfig The {@link ModuleConfig} for this request 117 * @return the <code>ForwardConfig</code> to be processed next (if any), 118 * or <code>null</code> if processing has been completed 119 * @throws Exception if there are any problems handling the exception 120 */ 121 protected abstract ForwardConfig handle(ActionContext context, 122 Exception exception, ExceptionConfig exceptionConfig, 123 ActionConfig actionConfig, ModuleConfig moduleConfig) 124 throws Exception; 125 }