/*
* $Id: ExceptionHandler.java 54929 2004-10-16 16:38:42Z germuska $
*
* Copyright 2001-2004 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.action;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.Globals;
import org.apache.struts.config.ExceptionConfig;
import org.apache.struts.util.MessageResources;
import org.apache.struts.util.ModuleException;
/**
* An ExceptionHandler is configured in the Struts
* configuration file to handle a specific type of exception thrown
* by an Action.execute method.
*
* @since Struts 1.1
*/
public class ExceptionHandler {
/**
* Commons logging instance.
*/
private static final Log log = LogFactory.getLog(ExceptionHandler.class);
/**
* The message resources for this package.
*/
private static MessageResources messages =
MessageResources.getMessageResources(
"org.apache.struts.action.LocalStrings");
/**
* Handle the Exception.
* Return the ActionForward instance (if any) returned by
* the called ExceptionHandler.
*
* @param ex The exception to handle
* @param ae The ExceptionConfig corresponding to the exception
* @param mapping The ActionMapping we are processing
* @param formInstance The ActionForm we are processing
* @param request The servlet request we are processing
* @param response The servlet response we are creating
*
* @exception ServletException if a servlet exception occurs
*
* @since Struts 1.1
*/
public ActionForward execute(
Exception ex,
ExceptionConfig ae,
ActionMapping mapping,
ActionForm formInstance,
HttpServletRequest request,
HttpServletResponse response)
throws ServletException {
ActionForward forward = null;
ActionMessage error = null;
String property = null;
// Build the forward from the exception mapping if it exists
// or from the form input
if (ae.getPath() != null) {
forward = new ActionForward(ae.getPath());
} else {
forward = mapping.getInputForward();
}
// Figure out the error
if (ex instanceof ModuleException) {
error = ((ModuleException) ex).getActionMessage();
property = ((ModuleException) ex).getProperty();
} else {
error = new ActionMessage(ae.getKey(), ex.getMessage());
property = error.getKey();
}
this.logException(ex);
// Store the exception
request.setAttribute(Globals.EXCEPTION_KEY, ex);
this.storeException(request, property, error, forward, ae.getScope());
return forward;
}
/**
* Logs the Exception using commons-logging.
* @param e The Exception to log.
* @since Struts 1.2
*/
protected void logException(Exception e){
log.debug(messages.getMessage("exception.log"), e);
}
/**
* Default implementation for handling an ActionError generated
* from an Exception during Action delegation. The default
* implementation is to set an attribute of the request or session, as
* defined by the scope provided (the scope from the exception mapping). An
* ActionErrors instance is created, the error is added to the collection
* and the collection is set under the Globals.ERROR_KEY.
*
* @param request The request we are handling
* @param property The property name to use for this error
* @param error The error generated from the exception mapping
* @param forward The forward generated from the input path (from the form or exception mapping)
* @param scope The scope of the exception mapping.
* @deprecated Use storeException(HttpServletRequest, String, ActionMessage, ActionForward, String)
* instead. This will be removed after Struts 1.2.
*/
protected void storeException(
HttpServletRequest request,
String property,
ActionError error,
ActionForward forward,
String scope) {
this.storeException(request, property, (ActionMessage) error, forward, scope);
// :TODO: Remove after Struts 1.2
}
/**
* Default implementation for handling an ActionMessage generated
* from an Exception during Action delegation. The default
* implementation is to set an attribute of the request or session, as
* defined by the scope provided (the scope from the exception mapping). An
* ActionMessages instance is created, the error is added to the
* collection and the collection is set under the Globals.ERROR_KEY.
*
* @param request The request we are handling
* @param property The property name to use for this error
* @param error The error generated from the exception mapping
* @param forward The forward generated from the input path (from the form or exception mapping)
* @param scope The scope of the exception mapping.
* @since Struts 1.2
*/
protected void storeException(
HttpServletRequest request,
String property,
ActionMessage error,
ActionForward forward,
String scope) {
ActionMessages errors = new ActionMessages();
errors.add(property, error);
if ("request".equals(scope)) {
request.setAttribute(Globals.ERROR_KEY, errors);
} else {
request.getSession().setAttribute(Globals.ERROR_KEY, errors);
}
}
}
