Java tutorial
/********************************************************************************** * $URL$ * $Id$ *********************************************************************************** * * Copyright (c) 2003, 2004, 2005, 2006 The Sakai Foundation. * * Licensed under the Educational Community License, Version 1.0 (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/ecl1.php * * 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 uk.ac.cam.caret.sakai.rwiki.tool; import org.sakaiproject.component.cover.ServerConfigurationService; import java.io.IOException; import java.util.Enumeration; 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.lang.StringUtils; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.sakaiproject.tool.api.Tool; import org.sakaiproject.tool.api.ToolSession; import org.sakaiproject.tool.cover.SessionManager; import org.springframework.web.context.WebApplicationContext; import org.springframework.web.context.support.WebApplicationContextUtils; import uk.ac.cam.caret.sakai.rwiki.tool.api.HttpCommand; import uk.ac.cam.caret.sakai.rwiki.tool.bean.PrePopulateBean; import uk.ac.cam.caret.sakai.rwiki.tool.bean.ViewBean; import uk.ac.cam.caret.sakai.rwiki.tool.command.Dispatcher; import uk.ac.cam.caret.sakai.rwiki.tool.command.SaveCommand; import uk.ac.cam.caret.sakai.rwiki.tool.util.WikiPageAction; import uk.ac.cam.caret.sakai.rwiki.utils.TimeLogger; /** * @author andrew */ public class RWikiServlet extends HttpServlet { private static Log log = LogFactory.getLog(RWikiServlet.class); /** * Required for serialization... also to stop eclipse from giving me a * warning! */ private static final long serialVersionUID = 676743152200357706L; public static final String SAVED_REQUEST_URL = "uk.ac.cam.caret.sakai.rwiki.tool.RWikiServlet.last-request-url"; private WebApplicationContext wac; private String headerPreContent; private String headerScriptSource; private String footerScript; private Dispatcher dispatcher = null; public void init(ServletConfig servletConfig) throws ServletException { super.init(servletConfig); ServletContext sc = servletConfig.getServletContext(); wac = WebApplicationContextUtils.getWebApplicationContext(sc); headerPreContent = servletConfig.getInitParameter("headerPreContent"); headerScriptSource = servletConfig.getInitParameter("headerScriptSource"); footerScript = servletConfig.getInitParameter("footerScript"); try { boolean logResponse = "true".equalsIgnoreCase(servletConfig.getInitParameter("log-response")); TimeLogger.setLogResponse(logResponse); } catch (Exception ex) { } try { boolean logFullResponse = "true".equalsIgnoreCase(servletConfig.getInitParameter("log-full-response")); TimeLogger.setLogFullResponse(logFullResponse); } catch (Exception ex) { } String basePath = servletConfig.getServletContext().getRealPath("/"); dispatcher = new MapDispatcher(sc); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { execute(request, response); } finally { RequestScopeSuperBean.clearInstance(); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { execute(request, response); } finally { RequestScopeSuperBean.clearInstance(); } } 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; } } log.debug("========================Page Start=========="); request.setAttribute(Tool.NATIVE_URL, Tool.NATIVE_URL); String targetURL = persistState(request); String action = request.getParameter("action"); if (!StringUtils.isEmpty(targetURL) && !StringUtils.equals(action, "search") && !StringUtils.equals(action, "full_search")) { response.sendRedirect(targetURL); return; } // Must be done on every request prePopulateRealm(request); addWikiStylesheet(request); request.setAttribute("footerScript", footerScript); if (headerScriptSource != null && headerScriptSource.length() > 0) { request.setAttribute("headerScriptSource", headerScriptSource); } RequestHelper helper = (RequestHelper) wac.getBean(RequestHelper.class.getName()); HttpCommand command = helper.getCommandForRequest(request); // fix for IE6's poor cache capabilities String userAgent = request.getHeader("User-Agent"); if (userAgent != null && userAgent.indexOf("MSIE 6") >= 0) { response.addHeader("Expires", "0"); response.addHeader("Pragma", "cache"); response.addHeader("Cache-Control", "private"); } command.execute(dispatcher, request, response); request.removeAttribute(Tool.NATIVE_URL); log.debug("=====================Page End============="); } public void prePopulateRealm(HttpServletRequest request) { RequestScopeSuperBean rssb = RequestScopeSuperBean.createAndAttach(request, wac); PrePopulateBean ppBean = rssb.getPrePopulateBean(); ppBean.doPrepopulate(); } public void addWikiStylesheet(HttpServletRequest request) { String sakaiHeader = (String) request.getAttribute("sakai.html.head"); request.setAttribute("sakai.html.head", headerPreContent + sakaiHeader); } /** * 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)) { if (log.isDebugEnabled()) { 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()); if (log.isDebugEnabled()) { 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 */ // XXX this should not be here!! The RequestHelper should perform this // functionality. private boolean isPageToolDefault(HttpServletRequest request) { // SAK-13408 - Tomcat and WAS have different URL structures; Attempting to add a // link or image would lead to site unavailable errors in websphere if the tomcat // URL structure is used. if ("websphere".equals(ServerConfigurationService.getString("servlet.container"))) { String tid = org.sakaiproject.tool.cover.ToolManager.getCurrentPlacement().getId(); if (request.getPathInfo() != null && request.getPathInfo().startsWith("/tool/" + tid + "/helper/")) { return false; } } else { if (request.getPathInfo() != null && request.getPathInfo().startsWith("/helper/")) { return false; } } String action = request.getParameter(RequestHelper.ACTION); if (action != null && action.length() > 0) { return false; } String pageName = request.getParameter(ViewBean.PAGE_NAME_PARAM); if (pageName == null || pageName.trim().length() == 0) { return true; } else { return false; } } /** * 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 (RequestHelper.TITLE_PANEL.equals(request.getParameter(RequestHelper.PANEL))) return false; if (WikiPageAction.PUBLICVIEW_ACTION.getName().equals(request.getParameter(RequestHelper.ACTION))) return false; if (WikiPageAction.PRINTVIEW_ACTION.getName().equals(request.getParameter(RequestHelper.ACTION))) return false; if ("GET".equalsIgnoreCase(request.getMethod())) return true; return false; } }