/*
* Copyright 2003,2004 The Apache Software Foundation.
*
* 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.apache.struts.chain;
import org.apache.commons.chain.Command;
import org.apache.commons.chain.Context;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.chain.Constants;
import org.apache.struts.config.ActionConfig;
import org.apache.struts.config.ExceptionConfig;
import org.apache.struts.config.ForwardConfig;
import org.apache.struts.config.ModuleConfig;
/**
* <p>Invoke the local or global exception handler configured for the
* exception class that occurred.</p>
*
* @author Craig R. McClanahan
* @version $Rev: 54933 $ $Date: 2004-10-16 18:04:52 +0100 (Sat, 16 Oct 2004) $
*/
public abstract class AbstractExceptionHandler implements Command {
// ------------------------------------------------------ Instance Variables
private String actionConfigKey = Constants.ACTION_CONFIG_KEY;
private String exceptionKey = Constants.EXCEPTION_KEY;
private String forwardConfigKey = Constants.FORWARD_CONFIG_KEY;
private String moduleConfigKey = Constants.MODULE_CONFIG_KEY;
private static final Log log =
LogFactory.getLog(AbstractExceptionHandler.class);
// -------------------------------------------------------------- Properties
/**
* <p>Return the context attribute key under which the
* <code>ActionConfig</code> for the currently selected application
* action is stored.</p>
*/
public String getActionConfigKey() {
return (this.actionConfigKey);
}
/**
* <p>Set the context attribute key under which the
* <code>ActionConfig</code> for the currently selected application
* action is stored.</p>
*
* @param actionConfigKey The new context attribute key
*/
public void setActionConfigKey(String actionConfigKey) {
this.actionConfigKey = actionConfigKey;
}
/**
* <p>Return the context attribute key under which any
* thrown exception will be stored.</p>
*/
public String getExceptionKey() {
return (this.exceptionKey);
}
/**
* <p>Set the context attribute key under which any
* thrown exception will be stored.</p>
*
* @param exceptionKey The new context attribute key
*/
public void setExceptionKey(String exceptionKey) {
this.exceptionKey = exceptionKey;
}
/**
* <p>Return the context attribute key under which the
* <code>ForwardConfig</code> for the currently selected application
* action is stored.</p>
*/
public String getForwardConfigKey() {
return (this.forwardConfigKey);
}
/**
* <p>Set the context attribute key under which the
* <code>ForwardConfig</code> for the currently selected application
* action is stored.</p>
*
* @param forwardConfigKey The new context attribute key
*/
public void setForwardConfigKey(String forwardConfigKey) {
this.forwardConfigKey = forwardConfigKey;
}
/**
* <p>Return the context attribute key under which the
* <code>ModuleConfig</code> for the currently selected application
* action is stored.</p>
*/
public String getModuleConfigKey() {
return (this.moduleConfigKey);
}
/**
* <p>Set the context attribute key under which the
* <code>ModuleConfig</code> for the currently selected application
* action is stored.</p>
*
* @param moduleConfigKey The new context attribute key
*/
public void setModuleConfigKey(String moduleConfigKey) {
this.moduleConfigKey = moduleConfigKey;
}
// ---------------------------------------------------------- Public Methods
/**
* <p>Invoke the appropriate <code>Action</code> for this request, and cache
* the returned <code>ActionForward</code>.</p>
*
* @param context The <code>Context</code> for the current request
*
* @exception InvalidPathException if no valid
* action can be identified for this request
*
* @return <code>false</code> if a <code>ForwardConfig</code> is returned,
* else <code>true</code> to complete processing
*/
public boolean execute(Context context) throws Exception {
// Look up the exception that was thrown
Exception exception = (Exception)
context.get(getExceptionKey());
if (exception == null) {
log.warn("No Exception found under key '" +
getExceptionKey() + "'");
return (true);
}
// Look up the local or global exception handler configuration
ExceptionConfig exceptionConfig = null;
ActionConfig actionConfig = (ActionConfig)
context.get(getActionConfigKey());
ModuleConfig moduleConfig = (ModuleConfig)
context.get(getModuleConfigKey());
if (actionConfig != null) {
log.debug("See if actionConfig " + actionConfig + " has an exceptionConfig for " + exception.getClass().getName());
exceptionConfig =
actionConfig.findException(exception.getClass());
}
// Handle the exception in the configured manner
if (exceptionConfig == null) {
log.warn("Unhandled exception", exception);
throw exception;
}
ForwardConfig forwardConfig =
handle(context, exception, exceptionConfig,
actionConfig, moduleConfig);
if (forwardConfig != null) {
context.put(getForwardConfigKey(), forwardConfig);
return (false);
} else {
return (true);
}
}
// ------------------------------------------------------- Protected Methods
/**
* <p>Perform the required handling of the specified exception.</p>
*
* @param context The <code>Context</code> for this request
* @param exception The exception being handled
* @param exceptionConfig The corresponding {@link ExceptionConfig}
* @param actionConfig The {@link ActionConfig} for this request
* @param moduleConfig The {@link ModuleConfig} for this request
*
* @return the <code>ForwardConfig</code> to be processed next (if any),
* or <code>null</code> if processing has been completed
*/
protected abstract ForwardConfig handle(Context context,
Exception exception,
ExceptionConfig exceptionConfig,
ActionConfig actionConfig,
ModuleConfig moduleConfig)
throws Exception;
}