/*
* $Id: DefinitionDispatcherAction.java 54929 2004-10-16 16:38:42Z germuska $
*
* Copyright 1999-2004 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.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;
import org.apache.struts.tiles.TilesUtil;
/**
* <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 useful in following situations:
* <li>
* <ul>To associate an Url to a definition</ul>
* <ul>To use Struts <html: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.
*
* @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $
*/
public 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) {
log.error("Can't get parameter '" + parameter + "'.");
return mapping.findForward("error");
}
// Try to dispatch to requested definition
try {
// Read definition from factory, but we can create it here.
ComponentDefinition definition =
TilesUtil.getDefinition(
name,
request,
getServlet().getServletContext());
if (log.isDebugEnabled()) {
log.debug("Get Definition " + definition);
}
DefinitionsUtil.setActionDefinition(request, definition);
} catch (FactoryNotFoundException e) {
log.error("Can't get definition factory.", e);
return mapping.findForward("error");
} catch (NoSuchDefinitionException e) {
log.error("Can't get definition '" + name + "'.", e);
return mapping.findForward("error");
} catch (DefinitionsFactoryException e) {
log.error("General Factory error '" + e.getMessage() + "'.", e);
return mapping.findForward("error");
} catch (Exception e) {
log.error("General error '" + e.getMessage() + "'.", e);
return mapping.findForward("error");
}
return mapping.findForward("success");
}
/**
* @deprecated This will be removed after Struts 1.2.
*/
protected void printError(HttpServletResponse response, String msg)
throws IOException {
response.setContentType("text/plain");
PrintWriter writer = response.getWriter();
writer.println(msg);
writer.flush();
writer.close();
}
}