src/main/java/net/pterodactylus/demoscenemusic/core/TemplateServlet.java

   1 /*
   2  * DemosceneMusic - TemplateServlet.java - Copyright © 2012 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.demoscenemusic.core;
  19
  20 import java.io.ByteArrayInputStream;
  21 import java.io.ByteArrayOutputStream;
  22 import java.io.IOException;
  23 import java.io.InputStream;
  24 import java.io.InputStreamReader;
  25 import java.io.Reader;
  26 import java.io.UnsupportedEncodingException;
  27 import java.lang.reflect.InvocationTargetException;
  28 import java.net.URISyntaxException;
  29 import java.util.Enumeration;
  30 import java.util.HashMap;
  31 import java.util.Map;
  32
  33 import javax.servlet.ServletConfig;
  34 import javax.servlet.ServletException;
  35 import javax.servlet.http.HttpServlet;
  36 import javax.servlet.http.HttpServletRequest;
  37 import javax.servlet.http.HttpServletResponse;
  38
  39 import net.pterodactylus.demoscenemusic.page.ServletRequest;
  40 import net.pterodactylus.util.io.Closer;
  41 import net.pterodactylus.util.io.StreamCopier;
  42 import net.pterodactylus.util.template.HtmlFilter;
  43 import net.pterodactylus.util.template.ReflectionAccessor;
  44 import net.pterodactylus.util.template.Template;
  45 import net.pterodactylus.util.template.TemplateContextFactory;
  46 import net.pterodactylus.util.template.TemplateParser;
  47 import net.pterodactylus.util.web.Header;
  48 import net.pterodactylus.util.web.Page;
  49 import net.pterodactylus.util.web.Response;
  50
  51 /**
  52  * TODO
  53  *
  54  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  55  */
  56 public class TemplateServlet extends HttpServlet {
  57
  58         private Core core;
  59         private final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  60
  61         private final Map<String, Page<ServletRequest>> pages = new HashMap<String, Page<ServletRequest>>();
  62
  63         //
  64         // SERVLET METHODS
  65         //
  66
  67         /**
  68          * {@inheritDoc}
  69          */
  70         @Override
  71         public void init(ServletConfig config) throws ServletException {
  72                 super.init(config);
  73                 core = (Core) config.getServletContext().getAttribute("core");
  74
  75                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  76
  77                 templateContextFactory.addFilter("html", new HtmlFilter());
  78
  79                 templateContextFactory.addTemplateObject("core", core);
  80                 templateContextFactory.addTemplateObject("dataManager", core.getDataManager());
  81
  82                 for (@SuppressWarnings("rawtypes")
  83                 Enumeration parameterNames = config.getInitParameterNames(); parameterNames.hasMoreElements();) {
  84                         String pageName = (String) parameterNames.nextElement();
  85                         Template template = getTemplate(pageName);
  86                         String pageClassName = config.getInitParameter(pageName);
  87                         try {
  88                                 Class<?> pageClass = Class.forName(pageClassName);
  89                                 @SuppressWarnings("unchecked")
  90                                 Page<ServletRequest> page = (Page<ServletRequest>) pageClass.getConstructor(Core.class, TemplateContextFactory.class, Template.class).newInstance(core, templateContextFactory, template);
  91                                 pages.put(pageName, page);
  92                         } catch (ClassNotFoundException cnfe1) {
  93                                 cnfe1.printStackTrace();
  94                         } catch (IllegalArgumentException iae1) {
  95                                 iae1.printStackTrace();
  96                         } catch (SecurityException se1) {
  97                                 se1.printStackTrace();
  98                         } catch (InstantiationException ie1) {
  99                                 ie1.printStackTrace();
 100                         } catch (IllegalAccessException iae1) {
 101                                 iae1.printStackTrace();
 102                         } catch (InvocationTargetException ite1) {
 103                                 ite1.printStackTrace();
 104                         } catch (NoSuchMethodException nsme1) {
 105                                 nsme1.printStackTrace();
 106                         }
 107                 }
 108         }
 109
 110         /**
 111          * {@inheritDoc}
 112          */
 113         @Override
 114         protected void doGet(HttpServletRequest request, HttpServletResponse httpServletResponse) throws ServletException, IOException {
 115                 String path = request.getPathInfo();
 116                 if (path.startsWith("/")) {
 117                         path = path.substring(1);
 118                 }
 119                 Page<ServletRequest> page = pages.get(path);
 120                 if (page != null) {
 121                         ServletRequest servletRequest;
 122                         try {
 123                                 servletRequest = new ServletRequest(request);
 124                         } catch (URISyntaxException use1) {
 125                                 throw new IOException("Could not create URI from " + request.getRequestURI(), use1);
 126                         }
 127                         ByteArrayOutputStream responseOutputBuffer = new ByteArrayOutputStream();
 128                         Response response = new Response(responseOutputBuffer);
 129                         response = page.handleRequest(servletRequest, response);
 130                         for (Header header : response.getHeaders()) {
 131                                 for (String value : header) {
 132                                         httpServletResponse.addHeader(header.getName(), value);
 133                                 }
 134                         }
 135                         httpServletResponse.setContentType(response.getContentType());
 136                         httpServletResponse.setStatus(response.getStatusCode());
 137                         StreamCopier.copy(new ByteArrayInputStream(responseOutputBuffer.toByteArray()), httpServletResponse.getOutputStream());
 138                         return;
 139                 }
 140         }
 141
 142         //
 143         // PRIVATE METHODS
 144         //
 145
 146         private Template getTemplate(String pageName) {
 147                 InputStream templateInputStream = getClass().getResourceAsStream("/templates/" + pageName);
 148                 if (templateInputStream == null) {
 149                         return null;
 150                 }
 151                 Reader templateReader = null;
 152                 try {
 153                         templateReader = new InputStreamReader(templateInputStream, "UTF-8");
 154                         return TemplateParser.parse(templateReader);
 155                 } catch (UnsupportedEncodingException uee1) {
 156                         /* can not happen. */
 157                         throw new RuntimeException("Could not parse templates!", uee1);
 158                 } finally {
 159                         Closer.close(templateReader);
 160                         Closer.close(templateInputStream);
 161                 }
 162         }
 163
 164 }