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.Comparator;
  30 import java.util.Enumeration;
  31 import java.util.HashMap;
  32 import java.util.Map;
  33
  34 import javax.servlet.ServletConfig;
  35 import javax.servlet.ServletException;
  36 import javax.servlet.http.HttpServlet;
  37 import javax.servlet.http.HttpServletRequest;
  38 import javax.servlet.http.HttpServletResponse;
  39
  40 import net.pterodactylus.demoscenemusic.data.Artist;
  41 import net.pterodactylus.demoscenemusic.page.ServletRequest;
  42 import net.pterodactylus.util.io.Closer;
  43 import net.pterodactylus.util.io.StreamCopier;
  44 import net.pterodactylus.util.template.ClassPathTemplateProvider;
  45 import net.pterodactylus.util.template.CollectionSortFilter;
  46 import net.pterodactylus.util.template.HtmlFilter;
  47 import net.pterodactylus.util.template.ReflectionAccessor;
  48 import net.pterodactylus.util.template.Template;
  49 import net.pterodactylus.util.template.TemplateContextFactory;
  50 import net.pterodactylus.util.template.TemplateParser;
  51 import net.pterodactylus.util.web.Header;
  52 import net.pterodactylus.util.web.Page;
  53 import net.pterodactylus.util.web.Response;
  54
  55 /**
  56  * TODO
  57  *
  58  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  59  */
  60 public class TemplateServlet extends HttpServlet {
  61
  62         private Core core;
  63         private final TemplateContextFactory templateContextFactory = new TemplateContextFactory();
  64
  65         private final Map<String, Page<ServletRequest>> pages = new HashMap<String, Page<ServletRequest>>();
  66
  67         //
  68         // SERVLET METHODS
  69         //
  70
  71         /**
  72          * {@inheritDoc}
  73          */
  74         @Override
  75         public void init(ServletConfig config) throws ServletException {
  76                 super.init(config);
  77                 core = (Core) config.getServletContext().getAttribute("core");
  78
  79                 templateContextFactory.addAccessor(Object.class, new ReflectionAccessor());
  80
  81                 templateContextFactory.addFilter("html", new HtmlFilter());
  82                 CollectionSortFilter sortFilter = new CollectionSortFilter();
  83                 sortFilter.addComparator(Artist.class, new Comparator<Artist>() {
  84
  85                         @Override
  86                         public int compare(Artist leftArtist, Artist rightArtist) {
  87                                 return leftArtist.name().compareToIgnoreCase(rightArtist.name());
  88                         }
  89
  90                 });
  91                 templateContextFactory.addFilter("sort", sortFilter);
  92
  93                 templateContextFactory.addTemplateObject("core", core);
  94                 templateContextFactory.addTemplateObject("dataManager", core.getDataManager());
  95
  96                 templateContextFactory.addProvider(new ClassPathTemplateProvider(getClass(), "/templates/"));
  97
  98                 for (@SuppressWarnings("rawtypes")
  99                 Enumeration parameterNames = config.getInitParameterNames(); parameterNames.hasMoreElements();) {
 100                         String pageName = (String) parameterNames.nextElement();
 101                         Template template = getTemplate(pageName);
 102                         String pageClassName = config.getInitParameter(pageName);
 103                         try {
 104                                 Class<?> pageClass = Class.forName(pageClassName);
 105                                 @SuppressWarnings("unchecked")
 106                                 Page<ServletRequest> page = (Page<ServletRequest>) pageClass.getConstructor(Core.class, TemplateContextFactory.class, Template.class).newInstance(core, templateContextFactory, template);
 107                                 pages.put(pageName, page);
 108                         } catch (ClassNotFoundException cnfe1) {
 109                                 cnfe1.printStackTrace();
 110                         } catch (IllegalArgumentException iae1) {
 111                                 iae1.printStackTrace();
 112                         } catch (SecurityException se1) {
 113                                 se1.printStackTrace();
 114                         } catch (InstantiationException ie1) {
 115                                 ie1.printStackTrace();
 116                         } catch (IllegalAccessException iae1) {
 117                                 iae1.printStackTrace();
 118                         } catch (InvocationTargetException ite1) {
 119                                 ite1.printStackTrace();
 120                         } catch (NoSuchMethodException nsme1) {
 121                                 nsme1.printStackTrace();
 122                         }
 123                 }
 124         }
 125
 126         /**
 127          * {@inheritDoc}
 128          */
 129         @Override
 130         protected void doGet(HttpServletRequest request, HttpServletResponse httpServletResponse) throws ServletException, IOException {
 131                 String path = request.getPathInfo();
 132                 if (path.startsWith("/")) {
 133                         path = path.substring(1);
 134                 }
 135                 Page<ServletRequest> page = pages.get(path);
 136                 if (page != null) {
 137                         ServletRequest servletRequest;
 138                         try {
 139                                 servletRequest = new ServletRequest(request);
 140                         } catch (URISyntaxException use1) {
 141                                 throw new IOException("Could not create URI from " + request.getRequestURI(), use1);
 142                         }
 143                         ByteArrayOutputStream responseOutputBuffer = new ByteArrayOutputStream();
 144                         Response response = new Response(responseOutputBuffer);
 145                         response = page.handleRequest(servletRequest, response);
 146                         for (Header header : response.getHeaders()) {
 147                                 for (String value : header) {
 148                                         httpServletResponse.addHeader(header.getName(), value);
 149                                 }
 150                         }
 151                         httpServletResponse.setContentType(response.getContentType());
 152                         httpServletResponse.setStatus(response.getStatusCode());
 153                         StreamCopier.copy(new ByteArrayInputStream(responseOutputBuffer.toByteArray()), httpServletResponse.getOutputStream());
 154                         return;
 155                 }
 156         }
 157
 158         //
 159         // PRIVATE METHODS
 160         //
 161
 162         private Template getTemplate(String pageName) {
 163                 InputStream templateInputStream = getClass().getResourceAsStream("/templates/" + pageName);
 164                 if (templateInputStream == null) {
 165                         return null;
 166                 }
 167                 Reader templateReader = null;
 168                 try {
 169                         templateReader = new InputStreamReader(templateInputStream, "UTF-8");
 170                         return TemplateParser.parse(templateReader);
 171                 } catch (UnsupportedEncodingException uee1) {
 172                         /* can not happen. */
 173                         throw new RuntimeException("Could not parse templates!", uee1);
 174                 } finally {
 175                         Closer.close(templateReader);
 176                         Closer.close(templateInputStream);
 177                 }
 178         }
 179
 180 }