Java tutorial
/* * $Id$ * * 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.result; import com.opensymphony.xwork2.ActionInvocation; import com.opensymphony.xwork2.inject.Inject; import org.apache.commons.lang3.ObjectUtils; import org.apache.commons.lang3.StringUtils; import org.apache.logging.log4j.LogManager; import org.apache.logging.log4j.Logger; import org.apache.struts2.ServletActionContext; import org.apache.struts2.StrutsStatics; import org.apache.struts2.dispatcher.HttpParameters; import org.apache.struts2.views.util.UrlHelper; import javax.servlet.RequestDispatcher; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.jsp.PageContext; import java.util.Map; /** * <!-- START SNIPPET: description --> * <p> * 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> * * <p> * There are three possible ways the result can be executed: * </p> * * <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 --> * * <p><b>This result type takes the following parameters:</b></p> * * <!-- 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 --> * * <p><b>Example:</b></p> * * <pre><!-- START SNIPPET: example --> * <result name="success" type="dispatcher"> * <param name="location">foo.jsp</param> * </result> * <!-- END SNIPPET: example --></pre> * * <p> * This result follows the same rules from {@link StrutsResultSupport}. * </p> * * @see javax.servlet.RequestDispatcher */ public class ServletDispatcherResult extends StrutsResultSupport { private static final long serialVersionUID = -1970659272360685627L; private static final Logger LOG = LogManager.getLogger(ServletDispatcherResult.class); private UrlHelper urlHelper; public ServletDispatcherResult() { super(); } public ServletDispatcherResult(String location) { super(location); } @Inject public void setUrlHelper(UrlHelper urlHelper) { this.urlHelper = urlHelper; } /** * 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 { 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); //add parameters passed on the location to #parameters // see WW-2120 if (StringUtils.isNotEmpty(finalLocation) && finalLocation.indexOf("?") > 0) { String queryString = finalLocation.substring(finalLocation.indexOf("?") + 1); HttpParameters parameters = getParameters(invocation); Map<String, Object> queryParams = urlHelper.parseQueryString(queryString, true); if (queryParams != null && !queryParams.isEmpty()) { parameters = HttpParameters.create(queryParams).withParent(parameters).build(); invocation.getInvocationContext().setParameters(parameters); // put to extraContext, see Dispatcher#createContextMap invocation.getInvocationContext().getContextMap().put("parameters", parameters); } } // if the view doesn't exist, let's do a 404 if (dispatcher == null) { LOG.warn("Location {} not found!", finalLocation); response.sendError(404, "result '" + finalLocation + "' not found"); return; } //if we are inside an action tag, we always need to do an include Boolean insideActionTag = (Boolean) ObjectUtils .defaultIfNull(request.getAttribute(StrutsStatics.STRUTS_ACTION_TAG_INVOCATION), Boolean.FALSE); // If we're included, then include the view // Otherwise do forward // This allow the page to, for example, set content type if (!insideActionTag && !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); } } } protected HttpParameters getParameters(ActionInvocation invocation) { return invocation.getInvocationContext().getParameters(); } }