wbx-lib.git - Ulrich Hilger Code Repository

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			package de.uhilger.wbx.web;

			/*
			WebBox - Dein Server.
			Copyright (C) 2019 Ulrich Hilger, http://uhilger.de

			This program is free software: you can redistribute it and/or modify
			it under the terms of the GNU Affero General Public License as
			published by the Free Software Foundation, either version 3 of the
			License, or (at your option) any later version.

			This program is distributed in the hope that it will be useful,
			but WITHOUT ANY WARRANTY; without even the implied warranty of
			MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
			GNU Affero General Public License for more details.

			You should have received a copy of the GNU Affero General Public License
			along with this program. If not, see <http://www.gnu.org/licenses/>.
			*/


			import java.io.IOException;
			import java.security.Principal;
			import java.util.logging.Level;
			import java.util.logging.Logger;
			import javax.servlet.ServletException;
			import javax.servlet.ServletOutputStream;
			import javax.servlet.http.HttpServletRequest;
			import javax.servlet.http.HttpServletResponse;
			import org.apache.catalina.servlets.DefaultServlet;

			/**
			* Das MdServlet fügt dem DefaultServlet von Tomcat
			* Methoden hinzu, mit denen Markdown-Inhalte (*.md)
			* zu ganzen HTML-Seiten
			* mit head und body tags sowie Stylesheet-Verweisen
			* ergänzt werden
			*
			* Die hier hinzugefuegten Inhalte verweisen lediglich auf
			* die Javscript-Biliothek strapdown.js
			* (http://strapdownjs.com), das Rendern
			* des Markdown zu HTML geschieht dann auf dem Client.
			*
			* TODO: Stylesheets dynamisch einbinden
			*/
			public class MdServlet extends DefaultServlet {

			private static final Logger logger = Logger.getLogger(MdServlet.class.getName());
			private static final String HOME_CTX = "/home";

			private String getTitle() {
			String title = null;
			return title;
			}

			private void seiteAusgeben(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {
			ServletOutputStream out = response.getOutputStream();
			printHeader(out, request);
			super.doGet(request, response);
			printFooter(out);
			}

			private void printHeader(ServletOutputStream out, HttpServletRequest request) throws IOException {
			out.print("<!DOCTYPE html>\r\n");
			out.print("<html><head>\r\n");
			out.print("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"/>\r\n");
			out.print("<meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">\r\n");
			out.print("<link rel=\"stylesheet\" type=\"text/css\" href=\"/jslib/sd/strapdown.css\">\r\n");
			String title = getTitle();
			if(title != null) {
			out.print("<title>");
			out.print(title);
			out.print(" ");
			out.print(request.getRequestURI());
			out.print("</title>\r\n");
			}
			out.print("</head><body>\r\n");
			out.print("<xmp theme=\"united\" style=\"display:none;\">\r\n");
			}

			private void printFooter(ServletOutputStream out) throws IOException {
			out.print("\r\n</xmp>\r\n");
			out.print("<script src=\"/jslib/sd/strapdown.js\"></script>\r\n");
			out.print("</body></html>");
			}

			/**
			* Handles the HTTP <code>GET</code> method.
			*
			* @param request servlet request
			* @param response servlet response
			* @throws ServletException if a servlet-specific error occurs
			* @throws IOException if an I/O error occurs
			*/
			@Override
			protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
			String contextPath = request.getContextPath();
			if(HOME_CTX.equals(contextPath)) {
			String userName = getUserName(request);
			if (userName != null) {
			String urlUser = getUrlUser(request, userName);
			if(userName.equals(urlUser)) {
			seiteAusgeben(request, response);
			} else {
			logger.fine("Wrong user.");
			}
			} else {
			logger.fine("Missing login.");
			}
			} else {
			seiteAusgeben(request, response);
			}
			}

			protected String getUrlUser(HttpServletRequest request, String userName) {
			String result = "";
			String requestUrlStr = request.getRequestURL().toString();
			String contextPath = request.getContextPath();
			if(contextPath != null && requestUrlStr != null && userName != null) {
			int start = requestUrlStr.indexOf(contextPath);
			start += contextPath.length();
			start++;
			int end = start + userName.length();
			try {
			result = requestUrlStr.substring(start, end);
			} catch(Exception ex) {
			logger.log(Level.SEVERE, ex.getLocalizedMessage(), ex);
			}
			}
			return result;
			}

			protected String getUserName(HttpServletRequest hr) {
			String userName = null;
			Object p = hr.getUserPrincipal();
			if (p instanceof Principal) {
			userName = ((Principal) p).getName();
			}
			return userName;
			}

			/**
			* Returns a short description of the servlet.
			*
			* @return a String containing servlet description
			*/
			@Override
			public String getServletInfo() {
			return "MarkdownWrapper Servlet";
			}

			}