/*
* $Id: ServletDispatcherResult.java 471756 2006-11-06 15:01:43Z husted $
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.struts2.dispatcher;
import javax.servlet.RequestDispatcher;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.PageContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionInvocation;
/**
* <!-- START SNIPPET: description -->
*
* Includes or forwards to a view (usually a jsp). Behind the scenes Struts
* will use a RequestDispatcher, where the target servlet/JSP receives the same
* request/response objects as the original servlet/JSP. Therefore, you can pass
* data between them using request.setAttribute() - the Struts action is
* available.
* <p/>
* There are three possible ways the result can be executed:
*
* <ul>
*
* <li>If we are in the scope of a JSP (a PageContext is available), PageContext's
* {@link PageContext#include(String) include} method is called.</li>
*
* <li>If there is no PageContext and we're not in any sort of include (there is no
* "javax.servlet.include.servlet_path" in the request attributes), then a call to
* {@link RequestDispatcher#forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse) forward}
* is made.</li>
*
* <li>Otherwise, {@link RequestDispatcher#include(javax.servlet.ServletRequest, javax.servlet.ServletResponse) include}
* is called.</li>
*
* </ul>
* <!-- END SNIPPET: description -->
*
* <b>This result type takes the following parameters:</b>
*
* <!-- START SNIPPET: params -->
*
* <ul>
*
* <li><b>location (default)</b> - the location to go to after execution (ex. jsp).</li>
*
* <li><b>parse</b> - true by default. If set to false, the location param will not be parsed for Ognl expressions.</li>
*
* </ul>
*
* <!-- END SNIPPET: params -->
*
* <b>Example:</b>
*
* <pre><!-- START SNIPPET: example -->
* <result name="success" type="dispatcher">
* <param name="location">foo.jsp</param>
* </result>
* <!-- END SNIPPET: example --></pre>
*
* This result follows the same rules from {@link StrutsResultSupport}.
*
* @see javax.servlet.RequestDispatcher
*/
public class ServletDispatcherResult extends StrutsResultSupport {
private static final long serialVersionUID = -1970659272360685627L;
private static final Log log = LogFactory.getLog(ServletDispatcherResult.class);
public ServletDispatcherResult() {
super();
}
public ServletDispatcherResult(String location) {
super(location);
}
/**
* Dispatches to the given location. Does its forward via a RequestDispatcher. If the
* dispatch fails a 404 error will be sent back in the http response.
*
* @param finalLocation the location to dispatch to.
* @param invocation the execution state of the action
* @throws Exception if an error occurs. If the dispatch fails the error will go back via the
* HTTP request.
*/
public void doExecute(String finalLocation, ActionInvocation invocation) throws Exception {
if (log.isDebugEnabled()) {
log.debug("Forwarding to location " + finalLocation);
}
PageContext pageContext = ServletActionContext.getPageContext();
if (pageContext != null) {
pageContext.include(finalLocation);
} else {
HttpServletRequest request = ServletActionContext.getRequest();
HttpServletResponse response = ServletActionContext.getResponse();
RequestDispatcher dispatcher = request.getRequestDispatcher(finalLocation);
// if the view doesn't exist, let's do a 404
if (dispatcher == null) {
response.sendError(404, "result '" + finalLocation + "' not found");
return;
}
// If we're included, then include the view
// Otherwise do forward
// This allow the page to, for example, set content type
if (!response.isCommitted() && (request.getAttribute("javax.servlet.include.servlet_path") == null)) {
request.setAttribute("struts.view_uri", finalLocation);
request.setAttribute("struts.request_uri", request.getRequestURI());
dispatcher.forward(request, response);
} else {
dispatcher.include(request, response);
}
}
}
}