/*
* $Header: /home/cvs/jakarta-struts/src/share/org/apache/struts/tiles/actions/DefinitionDispatcherAction.java,v 1.4 2002/11/16 04:18:59 jmitchell Exp $
* $Revision: 1.4 $
* $Date: 2002/11/16 04:18:59 $
*
* ====================================================================
*
* The Apache Software License, Version 1.1
*
* Copyright (c) 1999-2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Struts", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
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*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
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*
*/
package org.apache.struts.tiles.actions;
import java.io.IOException;
import java.io.PrintWriter;
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.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.tiles.ComponentDefinition;
import org.apache.struts.tiles.DefinitionsFactoryException;
import org.apache.struts.tiles.DefinitionsUtil;
import org.apache.struts.tiles.FactoryNotFoundException;
import org.apache.struts.tiles.NoSuchDefinitionException;
/**
* <p>An <strong>Action</strong> that dispatches to a Tiles Definition
* that is named by the request parameter whose name is specified
* by the <code>parameter</code> property of the corresponding
* ActionMapping.
* This action is usefull in following situations :
* <li>
* <ul>To associate an Url to a definition</ul>
* <ul>To use Struts <link> tag on a definition</ul>
* </li>
* <p>To configure the use of this action in your
* <code>struts-config.xml</code> file, create an entry like this:</p>
*
* <code>
* <action path="/saveSubscription"
* type="org.apache.struts.tiles.actions.DefinitionDispatcherAction"
* parameter="def"/>
* <forward name="success" path="anything" //>
* <forward name="error" path="path.to.error.page" //>
* </code>
*
* <p>which will use the value of the request parameter named "def"
* to pick the appropriate definition name.
* <p> The value for success doesn't matter. The forward will forward to
* appropriate definition.
* <p> The value for error should denote a valid jsp path or definition name.
*
* @author Niall Pemberton <niall.pemberton@btInternet.com>
* @author Craig R. McClanahan
* @author Cedric Dumoulin
* @version $Revision: 1.4 $ $Date: 2002/11/16 04:18:59 $
*/
public final class DefinitionDispatcherAction extends Action {
/** Commons Logging instance. */
protected static Log log = LogFactory.getLog(DefinitionDispatcherAction.class);
/**
* Process the specified HTTP request, and create the corresponding HTTP
* response (or forward to another web component that will create it),
* with provision for handling exceptions thrown by the business logic.
*
* @param mapping The ActionMapping used to select this instance
* @param form The optional ActionForm bean for this request (if any)
* @param request The HTTP request we are processing
* @param response The HTTP response we are creating
*
* @exception Exception if the application business logic throws
* an exception
* @since Struts 1.1
*/
public ActionForward execute(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
throws Exception
{
// Identify the request parameter containing the method name
// If none defined, use "def"
String parameter = mapping.getParameter();
if (parameter == null) {
parameter = "def";
}
// Identify the method name to be dispatched to
String name = request.getParameter(parameter);
if (name == null)
{
String msg = "Definition dispatcher action : can't get parameter '"
+ parameter + "'.";
printError( response, msg );
return (null);
}
// Try to dispatch to requested definition
try
{
// Read definition from factory, but we can create it here.
ComponentDefinition definition = DefinitionsUtil.getDefinition( name, request, getServlet().getServletContext() );
if(log.isDebugEnabled())
log.debug("get Definition " + definition );
DefinitionsUtil.setActionDefinition( request, definition);
}
catch( FactoryNotFoundException ex )
{
printError( response, "Error - DefinitionDispatcherAction : Can't get definition factory.");
return (mapping.findForward("error"));
}
catch( NoSuchDefinitionException ex )
{
printError( response, "Error - DefinitionDispatcherAction : Can't get definition '" + name +"'.");
return (mapping.findForward("error"));
}
catch( DefinitionsFactoryException ex )
{
printError( response, "Error - DefinitionDispatcherAction : General Factory error '" + ex.getMessage() +"'.");
return (mapping.findForward("error"));
}
catch( Exception ex )
{
printError( response, "Error - DefinitionDispatcherAction : General error '" + ex.getMessage() +"'.");
return (mapping.findForward("error"));
}
return (mapping.findForward("success"));
}
protected void printError( HttpServletResponse response, String msg )
throws IOException
{
response.setContentType("text/plain");
PrintWriter writer = response.getWriter();
writer.println(msg);
writer.flush();
writer.close();
}
}