zxingorg/src/com/google/zxing/web/DecodeServlet.java

   1 /*
   2  * Copyright 2008 Google Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package com.google.zxing.web;
  18
  19 import com.google.zxing.DecodeHintType;
  20 import com.google.zxing.MultiFormatReader;
  21 import com.google.zxing.Reader;
  22 import com.google.zxing.ReaderException;
  23 import com.google.zxing.Result;
  24 import com.google.zxing.client.j2se.BufferedImageMonochromeBitmapSource;
  25 import com.google.zxing.client.result.ParsedReaderResult;
  26 import org.apache.commons.fileupload.FileItem;
  27 import org.apache.commons.fileupload.FileUploadException;
  28 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
  29 import org.apache.commons.fileupload.servlet.ServletFileUpload;
  30 import org.apache.http.Header;
  31 import org.apache.http.HttpException;
  32 import org.apache.http.HttpMessage;
  33 import org.apache.http.HttpResponse;
  34 import org.apache.http.HttpVersion;
  35 import org.apache.http.client.HttpClient;
  36 import org.apache.http.client.methods.HttpGet;
  37 import org.apache.http.conn.PlainSocketFactory;
  38 import org.apache.http.conn.Scheme;
  39 import org.apache.http.conn.SchemeRegistry;
  40 import org.apache.http.conn.ssl.SSLSocketFactory;
  41 import org.apache.http.impl.client.DefaultHttpClient;
  42 import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
  43 import org.apache.http.params.BasicHttpParams;
  44 import org.apache.http.params.HttpParams;
  45 import org.apache.http.params.HttpProtocolParams;
  46
  47 import javax.imageio.ImageIO;
  48 import javax.mail.Authenticator;
  49 import javax.servlet.ServletConfig;
  50 import javax.servlet.ServletException;
  51 import javax.servlet.http.HttpServlet;
  52 import javax.servlet.http.HttpServletRequest;
  53 import javax.servlet.http.HttpServletResponse;
  54 import java.awt.image.BufferedImage;
  55 import java.io.IOException;
  56 import java.io.InputStream;
  57 import java.io.OutputStreamWriter;
  58 import java.io.Writer;
  59 import java.net.URI;
  60 import java.net.URISyntaxException;
  61 import java.net.UnknownHostException;
  62 import java.util.Hashtable;
  63 import java.util.List;
  64 import java.util.Timer;
  65 import java.util.logging.Logger;
  66
  67 /**
  68  * {@link HttpServlet} which decodes images containing barcodes. Given a URL, it will
  69  * retrieve the image and decode it. It can also process image files uploaded via POST.
  70  *
  71  * @author Sean Owen (srowen@google.com)
  72  */
  73 public final class DecodeServlet extends HttpServlet {
  74
  75   private static final long MAX_IMAGE_SIZE = 500000L;
  76   private static final long EMAIL_CHECK_INTERVAL = 2L * 60 * 1000;
  77
  78   private static final Logger log = Logger.getLogger(DecodeServlet.class.getName());
  79
  80   static final Hashtable<DecodeHintType, Object> HINTS;
  81
  82   static {
  83     HINTS = new Hashtable<DecodeHintType, Object>(3);
  84     HINTS.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
  85   }
  86
  87   private HttpClient client;
  88   private DiskFileItemFactory diskFileItemFactory;
  89   private Timer emailTimer;
  90
  91   @Override
  92   public void init(ServletConfig servletConfig) throws ServletException {
  93
  94     Logger logger = Logger.getLogger("com.google.zxing");
  95     logger.addHandler(new ServletContextLogHandler(servletConfig.getServletContext()));
  96
  97     String emailAddress = servletConfig.getInitParameter("emailAddress");
  98     String emailPassword = servletConfig.getInitParameter("emailPassword");
  99     if (emailAddress == null || emailPassword == null) {
 100       throw new ServletException("emailAddress or emailPassword not specified");
 101     }
 102
 103     HttpParams params = new BasicHttpParams();
 104     HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
 105
 106     SchemeRegistry registry = new SchemeRegistry();
 107     registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
 108     registry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
 109
 110     client = new DefaultHttpClient(new ThreadSafeClientConnManager(params, registry), params);
 111
 112     diskFileItemFactory = new DiskFileItemFactory();
 113
 114     Authenticator emailAuthenticator = new EmailAuthenticator(emailAddress, emailPassword);
 115     emailTimer = new Timer("Email decoder timer", true);
 116     emailTimer.schedule(new DecodeEmailTask(emailAddress, emailAuthenticator), 0L, EMAIL_CHECK_INTERVAL);
 117
 118     log.info("DecodeServlet configured");
 119   }
 120
 121   @Override
 122   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 123
 124     String imageURIString = request.getParameter("u");
 125     if (imageURIString == null || imageURIString.length() == 0) {
 126       response.sendRedirect("badurl.jspx");
 127       return;
 128     }
 129
 130     if (!(imageURIString.startsWith("http://") || imageURIString.startsWith("https://"))) {
 131       imageURIString = "http://" + imageURIString;
 132     }
 133
 134     URI imageURI;
 135     try {
 136       imageURI = new URI(imageURIString);
 137     } catch (URISyntaxException urise) {
 138       response.sendRedirect("badurl.jspx");
 139       return;
 140     }
 141
 142     HttpGet getRequest = new HttpGet(imageURI);
 143
 144     try {
 145       HttpResponse getResponse = client.execute(getRequest);
 146       if (getResponse.getStatusLine().getStatusCode() != HttpServletResponse.SC_OK) {
 147         response.sendRedirect("badurl.jspx");
 148         return;
 149       }
 150       if (!isSizeOK(getResponse)) {
 151         response.sendRedirect("badimage.jspx");
 152         return;
 153       }
 154       log.info("Decoding " + imageURI);
 155       InputStream is = getResponse.getEntity().getContent();
 156       try {
 157         processStream(is, request, response);
 158       } finally {
 159         is.close();
 160       }
 161     } catch (InterruptedException ie) {
 162       getRequest.abort();
 163       response.sendRedirect("badurl.jspx");
 164     } catch (HttpException he) {
 165       getRequest.abort();
 166       response.sendRedirect("badurl.jspx");
 167     } catch (UnknownHostException uhe) {
 168       getRequest.abort();
 169       response.sendRedirect("badurl.jspx");
 170     }
 171
 172   }
 173
 174   @Override
 175   protected void doPost(HttpServletRequest request, HttpServletResponse response)
 176           throws ServletException, IOException {
 177
 178     if (!ServletFileUpload.isMultipartContent(request)) {
 179       response.sendRedirect("badimage.jspx");
 180       return;
 181     }
 182
 183     ServletFileUpload upload = new ServletFileUpload(diskFileItemFactory);
 184     upload.setFileSizeMax(MAX_IMAGE_SIZE);
 185
 186     // Parse the request
 187     try {
 188       for (FileItem item : (List<FileItem>) upload.parseRequest(request)) {
 189         if (!item.isFormField()) {
 190           if (item.getSize() <= MAX_IMAGE_SIZE) {
 191             log.info("Decoding uploaded file");
 192             InputStream is = item.getInputStream();
 193             try {
 194               processStream(is, request, response);
 195             } finally {
 196               is.close();
 197             }
 198           } else {
 199             response.sendRedirect("badimage.jspx");
 200           }
 201           break;
 202         }
 203       }
 204     } catch (FileUploadException fue) {
 205       response.sendRedirect("badimage.jspx");
 206     }
 207
 208   }
 209
 210   private static void processStream(InputStream is, HttpServletRequest request, HttpServletResponse response)
 211       throws ServletException, IOException {
 212     BufferedImage image = ImageIO.read(is);
 213     if (image == null) {
 214       response.sendRedirect("badimage.jspx");
 215       return;
 216     }
 217
 218     Reader reader = new MultiFormatReader();
 219     Result result;
 220     try {
 221       result = reader.decode(new BufferedImageMonochromeBitmapSource(image), HINTS);
 222     } catch (ReaderException re) {
 223       log.info("DECODE FAILED: " + re.toString());
 224       response.sendRedirect("notfound.jspx");
 225       return;
 226     }
 227
 228     if (request.getParameter("full") == null) {
 229       response.setContentType("text/plain");
 230       response.setCharacterEncoding("UTF-8");
 231       Writer out = new OutputStreamWriter(response.getOutputStream(), "UTF-8");
 232       try {
 233         out.write(result.getText());
 234       } finally {
 235         out.close();
 236       }
 237     } else {
 238       request.setAttribute("result", result);
 239       ParsedReaderResult parsedReaderResult = ParsedReaderResult.parseReaderResult(result);
 240       request.setAttribute("parsedReaderResult", parsedReaderResult);
 241       request.getRequestDispatcher("decoderesult.jspx").forward(request, response);
 242     }
 243   }
 244
 245   private static boolean isSizeOK(HttpMessage getResponse) {
 246     Header lengthHeader = getResponse.getLastHeader("Content-Length");
 247     if (lengthHeader != null) {
 248       long length = Long.parseLong(lengthHeader.getValue());
 249       if (length > MAX_IMAGE_SIZE) {
 250         return false;
 251       }
 252     }
 253     return true;
 254   }
 255
 256   @Override
 257   public void destroy() {
 258     log.config("DecodeServlet shutting down...");
 259     emailTimer.cancel();
 260   }
 261
 262 }