Android/r2-streamer/r2-server/src/main/java/org/readium/r2_streamer/server/handler/ResourceHandler.java

   1 package org.readium.r2_streamer.server.handler;
   2
   3 import org.readium.r2_streamer.fetcher.EpubFetcher;
   4 import org.readium.r2_streamer.fetcher.EpubFetcherException;
   5 import org.readium.r2_streamer.model.publication.Encryption;
   6 import org.readium.r2_streamer.model.publication.link.Link;
   7 import org.readium.r2_streamer.parser.EncryptionDecoder;
   8 import org.readium.r2_streamer.server.ResponseStatus;
   9
  10 import java.io.IOException;
  11 import java.io.InputStream;
  12 import java.util.Map;
  13
  14 import fi.iki.elonen.NanoHTTPD;
  15 import fi.iki.elonen.NanoHTTPD.IHTTPSession;
  16 import fi.iki.elonen.NanoHTTPD.Method;
  17 import fi.iki.elonen.NanoHTTPD.Response;
  18 import fi.iki.elonen.NanoHTTPD.Response.IStatus;
  19 import fi.iki.elonen.NanoHTTPD.Response.Status;
  20 import fi.iki.elonen.router.RouterNanoHTTPD.DefaultHandler;
  21 import fi.iki.elonen.router.RouterNanoHTTPD.UriResource;
  22
  23 import static fi.iki.elonen.NanoHTTPD.MIME_PLAINTEXT;
  24
  25 /**
  26  * Created by Shrikant Badwaik on 10-Feb-17.
  27  */
  28
  29 public class ResourceHandler extends DefaultHandler {
  30     private static final String TAG = "ResourceHandler";
  31
  32     public ResourceHandler() {
  33     }
  34
  35     @Override
  36     public String getMimeType() {
  37         return null;
  38     }
  39
  40     private final String[] fonts = {".woff", ".ttf", ".obf", ".woff2", ".eot", ".otf"};
  41
  42     @Override
  43     public String getText() {
  44         return ResponseStatus.FAILURE_RESPONSE;
  45     }
  46
  47     @Override
  48     public IStatus getStatus() {
  49         return Status.OK;
  50     }
  51
  52     @Override
  53     public Response get(UriResource uriResource, Map<String, String> urlParams, IHTTPSession session) {
  54         Method method = session.getMethod();
  55         String uri = session.getUri();
  56
  57         System.out.println(TAG + " Method: " + method + ", Url: " + uri);
  58
  59         try {
  60             EpubFetcher fetcher = uriResource.initParameter(EpubFetcher.class);
  61             int offset = uri.indexOf("/", 0);
  62             int startIndex = uri.indexOf("/", offset + 1);
  63             String filePath = uri.substring(startIndex + 1);
  64             Link link = fetcher.publication.getResourceMimeType(filePath);
  65             String mimeType = link.getTypeLink();
  66
  67             // If the content is of type html return the response this is done to
  68             // skip the check for following font deobfuscation check
  69             if (mimeType.equals("application/xhtml+xml")) {
  70                 return serveResponse(session, fetcher.getDataInputStream(filePath), mimeType);
  71             }
  72
  73             // ********************
  74             //  FONT DEOBFUSCATION
  75             // ********************
  76             if (isFontFile(filePath)) { // Check if the incoming request for the font file is encrypted
  77                 Encryption encryption = Encryption.getEncryptionFormFontFilePath(
  78                         filePath,
  79                         fetcher.publication.encryptions);
  80                 if (encryption != null) { // Decode the font file if encryption exists
  81                     return serveResponse(session,
  82                             EncryptionDecoder.decode(
  83                                     fetcher.publication.metadata.identifier,
  84                                     fetcher.getDataInputStream(encryption.getProfile()),
  85                                     encryption),
  86                             mimeType);
  87                 }
  88             }
  89             return serveResponse(session, fetcher.getDataInputStream(filePath), mimeType);
  90         } catch (EpubFetcherException e) {
  91             System.out.println(TAG + " EpubFetcherException " + e.toString());
  92             return NanoHTTPD.newFixedLengthResponse(Status.INTERNAL_ERROR, getMimeType(), ResponseStatus.FAILURE_RESPONSE);
  93         }
  94     }
  95
  96     private Response serveResponse(IHTTPSession session, InputStream inputStream, String mimeType) {
  97         Response response;
  98         String rangeRequest = session.getHeaders().get("range");
  99
 100         try {
 101             // Calculate etag
 102             String etag = Integer.toHexString(inputStream.hashCode());
 103
 104             // Support skipping:
 105             long startFrom = 0;
 106             long endAt = -1;
 107             if (rangeRequest != null) {
 108                 if (rangeRequest.startsWith("bytes=")) {
 109                     rangeRequest = rangeRequest.substring("bytes=".length());
 110                     int minus = rangeRequest.indexOf('-');
 111                     try {
 112                         if (minus > 0) {
 113                             startFrom = Long.parseLong(rangeRequest.substring(0, minus));
 114                             endAt = Long.parseLong(rangeRequest.substring(minus + 1));
 115                         }
 116                     } catch (NumberFormatException ignored) {
 117                     }
 118                 }
 119             }
 120
 121             // Change return code and add Content-Range header when skipping is requested
 122             long streamLength = inputStream.available();
 123             if (rangeRequest != null && startFrom >= 0) {
 124                 if (startFrom >= streamLength) {
 125                     response = createResponse(Response.Status.RANGE_NOT_SATISFIABLE, MIME_PLAINTEXT, "");
 126                     response.addHeader("Content-Range", "bytes 0-0/" + streamLength);
 127                     response.addHeader("ETag", etag);
 128                 } else {
 129                     if (endAt < 0) {
 130                         endAt = streamLength - 1;
 131                     }
 132                     long newLen = endAt - startFrom + 1;
 133                     if (newLen < 0) {
 134                         newLen = 0;
 135                     }
 136
 137                     final long dataLen = newLen;
 138                     inputStream.skip(startFrom);
 139
 140                     response = createResponse(Response.Status.PARTIAL_CONTENT, mimeType, inputStream);
 141                     response.addHeader("Content-Length", "" + dataLen);
 142                     response.addHeader("Content-Range", "bytes " + startFrom + "-" + endAt + "/" + streamLength);
 143                     response.addHeader("ETag", etag);
 144                 }
 145             } else {
 146                 if (etag.equals(session.getHeaders().get("if-none-match")))
 147                     response = createResponse(Response.Status.NOT_MODIFIED, mimeType, "");
 148                 else {
 149                     response = createResponse(Response.Status.OK, mimeType, inputStream);
 150                     response.addHeader("Content-Length", "" + streamLength);
 151                     response.addHeader("ETag", etag);
 152                 }
 153             }
 154         } catch (IOException | NullPointerException ioe) {
 155             response = getResponse("Forbidden: Reading file failed");
 156         }
 157
 158         return (response == null) ? getResponse("Error 404: File not found") : response;
 159     }
 160
 161     private Response createResponse(Status status, String mimeType, InputStream message) {
 162         Response response = NanoHTTPD.newChunkedResponse(status, mimeType, message);
 163         response.addHeader("Accept-Ranges", "bytes");
 164         return response;
 165     }
 166
 167     private Response createResponse(Status status, String mimeType, String message) {
 168         Response response = NanoHTTPD.newFixedLengthResponse(status, mimeType, message);
 169         response.addHeader("Accept-Ranges", "bytes");
 170         return response;
 171     }
 172
 173     private Response getResponse(String message) {
 174         return createResponse(Response.Status.OK, "text/plain", message);
 175     }
 176
 177     private boolean isFontFile(String file) {
 178         for (String font : fonts) {
 179             if (file.endsWith(font)) {
 180                 return true;
 181             }
 182         }
 183         return false;
 184     }
 185 }