src/main/java/net/pterodactylus/sone/web/ajax/JsonPage.java

   1 /*
   2  * Sone - JsonPage.java - Copyright © 2010–2016 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.sone.web.ajax;
  19
  20 import static java.util.logging.Logger.getLogger;
  21
  22 import java.io.ByteArrayOutputStream;
  23 import java.io.IOException;
  24 import java.io.OutputStreamWriter;
  25 import java.io.PrintWriter;
  26 import java.net.URI;
  27 import java.util.logging.Level;
  28 import java.util.logging.Logger;
  29
  30 import net.pterodactylus.sone.data.Sone;
  31 import net.pterodactylus.sone.web.WebInterface;
  32 import net.pterodactylus.sone.web.page.FreenetPage;
  33 import net.pterodactylus.sone.web.page.FreenetRequest;
  34 import net.pterodactylus.util.io.Closer;
  35 import net.pterodactylus.util.web.Page;
  36 import net.pterodactylus.util.web.Response;
  37
  38 import com.fasterxml.jackson.databind.ObjectMapper;
  39 import freenet.clients.http.SessionManager.Session;
  40 import freenet.clients.http.ToadletContext;
  41
  42 /**
  43  * A JSON page is a specialized {@link Page} that will always return a JSON
  44  * object to the browser, e.g. for use with AJAX or other scripting frameworks.
  45  *
  46  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  47  */
  48 public abstract class JsonPage implements FreenetPage {
  49
  50         /** The logger. */
  51         private static final Logger logger = getLogger(JsonPage.class.getName());
  52
  53         /** The JSON serializer. */
  54         private static final ObjectMapper objectMapper = new ObjectMapper();
  55
  56         /** The path of the page. */
  57         private final String path;
  58
  59         /** The Sone web interface. */
  60         protected final WebInterface webInterface;
  61
  62         /**
  63          * Creates a new JSON page at the given path.
  64          *
  65          * @param path
  66          *            The path of the page
  67          * @param webInterface
  68          *            The Sone web interface
  69          */
  70         public JsonPage(String path, WebInterface webInterface) {
  71                 this.path = path;
  72                 this.webInterface = webInterface;
  73         }
  74
  75         //
  76         // ACCESSORS
  77         //
  78
  79         /**
  80          * Returns the currently logged in Sone.
  81          *
  82          * @param toadletContext
  83          *            The toadlet context
  84          * @return The currently logged in Sone, or {@code null} if no Sone is
  85          *         currently logged in
  86          */
  87         protected Sone getCurrentSone(ToadletContext toadletContext) {
  88                 return webInterface.getCurrentSoneCreatingSession(toadletContext);
  89         }
  90
  91         protected Sone getCurrentSoneWithoutCreatingSession(ToadletContext toadletContext) {
  92                 return webInterface.getCurrentSoneWithoutCreatingSession(toadletContext);
  93         }
  94
  95         //
  96         // METHODS FOR SUBCLASSES TO OVERRIDE
  97         //
  98
  99         /**
 100          * This method is called to create the JSON object that is returned back to
 101          * the browser.
 102          *
 103          * @param request
 104          *            The request to handle
 105          * @return The created JSON object
 106          */
 107         protected abstract JsonReturnObject createJsonObject(FreenetRequest request);
 108
 109         /**
 110          * Returns whether this command needs the form password for authentication
 111          * and to prevent abuse.
 112          *
 113          * @return {@code true} if the form password (given as “formPassword”) is
 114          *         required, {@code false} otherwise
 115          */
 116         @SuppressWarnings("static-method")
 117         protected boolean needsFormPassword() {
 118                 return true;
 119         }
 120
 121         /**
 122          * Returns whether this page requires the user to be logged in.
 123          *
 124          * @return {@code true} if the user needs to be logged in to use this page,
 125          *         {@code false} otherwise
 126          */
 127         @SuppressWarnings("static-method")
 128         protected boolean requiresLogin() {
 129                 return true;
 130         }
 131
 132         //
 133         // PROTECTED METHODS
 134         //
 135
 136         /**
 137          * Creates a success reply.
 138          *
 139          * @return A reply signaling success
 140          */
 141         protected static JsonReturnObject createSuccessJsonObject() {
 142                 return new JsonReturnObject(true);
 143         }
 144
 145         /**
 146          * Creates an error reply.
 147          *
 148          * @param error
 149          *            The error that has occured
 150          * @return The JSON object, signalling failure and the error code
 151          */
 152         protected static JsonReturnObject createErrorJsonObject(String error) {
 153                 return new JsonErrorReturnObject(error);
 154         }
 155
 156         //
 157         // PAGE METHODS
 158         //
 159
 160         /**
 161          * {@inheritDoc}
 162          */
 163         @Override
 164         public String getPath() {
 165                 return path;
 166         }
 167
 168         /**
 169          * {@inheritDoc}
 170          */
 171         @Override
 172         public boolean isPrefixPage() {
 173                 return false;
 174         }
 175
 176         /**
 177          * {@inheritDoc}
 178          */
 179         @Override
 180         public Response handleRequest(FreenetRequest request, Response response) throws IOException {
 181                 if (webInterface.getCore().getPreferences().isRequireFullAccess() && !request.getToadletContext().isAllowedFullAccess()) {
 182                         return response.setStatusCode(403).setStatusText("Forbidden").setContentType("application/json").write(objectMapper.writeValueAsString(new JsonErrorReturnObject("auth-required")));
 183                 }
 184                 if (needsFormPassword()) {
 185                         String formPassword = request.getHttpRequest().getParam("formPassword");
 186                         if (!webInterface.getFormPassword().equals(formPassword)) {
 187                                 return response.setStatusCode(403).setStatusText("Forbidden").setContentType("application/json").write(objectMapper.writeValueAsString(new JsonErrorReturnObject("auth-required")));
 188                         }
 189                 }
 190                 if (requiresLogin()) {
 191                         if (getCurrentSoneWithoutCreatingSession(request.getToadletContext()) == null) {
 192                                 return response.setStatusCode(403).setStatusText("Forbidden").setContentType("application/json").write(objectMapper.writeValueAsString(new JsonErrorReturnObject("auth-required")));
 193                         }
 194                 }
 195                 try {
 196                         JsonReturnObject jsonObject = createJsonObject(request);
 197                         return response.setStatusCode(200).setStatusText("OK").setContentType("application/json").write(objectMapper.writeValueAsString(jsonObject));
 198                 } catch (Exception e1) {
 199                         logger.log(Level.WARNING, "Error executing JSON page!", e1);
 200                         return response.setStatusCode(500).setStatusText(e1.getMessage()).setContentType("text/plain").write(dumpStackTrace(e1));
 201                 }
 202         }
 203
 204         /**
 205          * {@inheritDoc}
 206          */
 207         @Override
 208         public boolean isLinkExcepted(URI link) {
 209                 return false;
 210         }
 211
 212         //
 213         // PRIVATE METHODS
 214         //
 215
 216         /**
 217          * Returns a byte array containing the stack trace of the given throwable.
 218          *
 219          * @param t
 220          *            The throwable whose stack trace to dump into an array
 221          * @return The array with the stack trace, or an empty array if the stack
 222          *         trace could not be dumped
 223          */
 224         private static byte[] dumpStackTrace(Throwable t) {
 225                 ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
 226                 OutputStreamWriter writer = null;
 227                 PrintWriter printWriter = null;
 228                 try {
 229                         writer = new OutputStreamWriter(byteArrayOutputStream, "uTF-8");
 230                         printWriter = new PrintWriter(writer);
 231                         t.printStackTrace(printWriter);
 232                         byteArrayOutputStream.flush();
 233                         return byteArrayOutputStream.toByteArray();
 234                 } catch (IOException ioe1) {
 235                         /* quite not possible. */
 236                         return new byte[0];
 237                 } finally {
 238                         Closer.close(printWriter);
 239                         Closer.close(writer);
 240                         Closer.close(byteArrayOutputStream);
 241                 }
 242         }
 243
 244 }