Java tutorial
/********************************************************************************** * $URL$ * $Id$ *********************************************************************************** * * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 The Sakai Foundation * * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.search.tool; import java.io.IOException; import javax.servlet.RequestDispatcher; import javax.servlet.ServletConfig; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.sakaiproject.search.tool.api.SearchBeanFactory; import org.sakaiproject.tool.api.SessionManager; import org.sakaiproject.tool.api.Tool; import org.sakaiproject.tool.api.ToolSession; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.context.support.WebApplicationContextUtils; /** * @author Ian Boston */ public class ControllerServlet extends HttpServlet { public static final Log log = LogFactory.getLog(ControllerServlet.class); /** * Required for serialization... also to stop eclipse from giving me a * warning! */ private static final long serialVersionUID = 676743152200357708L; public static final String SAVED_REQUEST_URL = "org.sakaiproject.search.api.last-request-url"; private static final String PANEL = "panel"; private static final Object TITLE_PANEL = "Title"; private WebApplicationContext wac; private SearchBeanFactory searchBeanFactory = null; private SessionManager sessionManager; public void init(ServletConfig servletConfig) throws ServletException { super.init(servletConfig); ServletContext sc = servletConfig.getServletContext(); wac = WebApplicationContextUtils.getWebApplicationContext(sc); try { searchBeanFactory = (SearchBeanFactory) wac.getBean("search-searchBeanFactory"); ServletContext context = getServletContext(); searchBeanFactory.setContext(context); } catch (Exception ex) { int x = 1; //ignore } if (sessionManager == null) { sessionManager = (SessionManager) wac.getBean(SessionManager.class.getName()); } } protected void doGet(final HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { execute(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { execute(request, response); } public void execute(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { if (wac == null) { wac = WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext()); if (wac == null) { response.sendError(HttpServletResponse.SC_SERVICE_UNAVAILABLE, "Cannot get WebApplicationContext"); return; } } request.setAttribute(Tool.NATIVE_URL, Tool.NATIVE_URL); if (searchBeanFactory == null) { searchBeanFactory = (SearchBeanFactory) wac.getBean("search-searchBeanFactory"); ServletContext context = getServletContext(); searchBeanFactory.setContext(context); } if (sessionManager == null) { sessionManager = (SessionManager) wac.getBean(SessionManager.class.getName()); } addLocalHeaders(request); String targetURL = persistState(request); if (targetURL != null && targetURL.trim().length() > 0) { response.sendRedirect(targetURL); return; } if (TITLE_PANEL.equals(request.getParameter(PANEL))) { String targetPage = "/WEB-INF/pages/title.jsp"; RequestDispatcher rd = request.getRequestDispatcher(targetPage); rd.forward(request, response); } else { String path = request.getPathInfo(); if (path == null || path.length() == 0) { path = "/index"; } if (!path.startsWith("/")) { path = "/" + path; } String targetPage = "/WEB-INF/pages" + path + ".jsp"; request.setAttribute(SearchBeanFactory.SEARCH_BEAN_FACTORY_ATTR, searchBeanFactory); RequestDispatcher rd = request.getRequestDispatcher(targetPage); rd.forward(request, response); } request.removeAttribute(Tool.NATIVE_URL); } public void addLocalHeaders(HttpServletRequest request) { String sakaiHeader = (String) request.getAttribute("sakai.html.head"); String skin = "default/"; // this could be changed in the future to // make search skin awaire String localStylesheet = "<link href=\"/sakai-search-tool/styles/" + skin + "searchStyle.css\" type=\"text/css\" rel=\"stylesheet\" media=\"all\" />"; String localJavascript = "<script type=\"text/javascript\" src=\"/sakai-search-tool/scripts/search.js\"> </script>"; request.setAttribute("sakai.html.head", localStylesheet + sakaiHeader + localJavascript); } /** * returns the request state for the tool. If the state is restored, we set * the request attribute RWikiServlet.REQUEST_STATE_RESTORED to Boolean.TRUE * and a Thread local named RWikiServlet.REQUEST_STATE_RESTORED to * Boolean.TRUE. These MUST be checked by anything that modifies state, to * ensure that a reinitialisation of Tool state does not result in a repost * of data. * * @param request * @return */ private String persistState(HttpServletRequest request) { ToolSession ts = sessionManager.getCurrentToolSession(); if (isPageToolDefault(request)) { log.debug("Incomming URL is " + request.getRequestURL().toString() + "?" + request.getQueryString()); log.debug("Restore " + ts.getAttribute(SAVED_REQUEST_URL)); return (String) ts.getAttribute(SAVED_REQUEST_URL); } if (isPageRestorable(request)) { ts.setAttribute(SAVED_REQUEST_URL, request.getRequestURL().toString() + "?" + request.getQueryString()); log.debug("Saved " + ts.getAttribute(SAVED_REQUEST_URL)); } return null; } /** * Check to see if the reques represents the Tool default page. This is not * the same as the view Home. It is the same as first entry into a Tool or * when the page is refreshed * * @param request * @return true if the page is the Tool default page */ private boolean isPageToolDefault(HttpServletRequest request) { if (TITLE_PANEL.equals(request.getParameter(PANEL))) return false; String pathInfo = request.getPathInfo(); String queryString = request.getQueryString(); String method = request.getMethod(); return ("GET".equalsIgnoreCase(method) && (pathInfo == null || request.getPathInfo().length() == 0) && (queryString == null || queryString.length() == 0)); } /** * Check to see if the request represents a page that can act as a restor * point. * * @param request * @return true if it is possible to restore to this point. */ private boolean isPageRestorable(HttpServletRequest request) { if (TITLE_PANEL.equals(request.getParameter(PANEL))) return false; String pathInfo = request.getPathInfo(); if (pathInfo != null) { if (request.getPathInfo().endsWith(".gif")) { return false; } if (request.getPathInfo().endsWith(".src")) { return false; } } if ("GET".equalsIgnoreCase(request.getMethod())) return true; return false; } }