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

   1 /*
   2  * Copyright 2008 ZXing authors
   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.ParsedResult;
  26 import com.google.zxing.client.result.ResultParser;
  27 import org.apache.commons.fileupload.FileItem;
  28 import org.apache.commons.fileupload.FileUploadException;
  29 import org.apache.commons.fileupload.disk.DiskFileItemFactory;
  30 import org.apache.commons.fileupload.servlet.ServletFileUpload;
  31 import org.apache.http.Header;
  32 import org.apache.http.HttpException;
  33 import org.apache.http.HttpMessage;
  34 import org.apache.http.HttpResponse;
  35 import org.apache.http.HttpVersion;
  36 import org.apache.http.client.HttpClient;
  37 import org.apache.http.client.methods.HttpGet;
  38 import org.apache.http.conn.PlainSocketFactory;
  39 import org.apache.http.conn.Scheme;
  40 import org.apache.http.conn.SchemeRegistry;
  41 import org.apache.http.conn.ssl.SSLSocketFactory;
  42 import org.apache.http.impl.client.DefaultHttpClient;
  43 import org.apache.http.impl.conn.tsccm.ThreadSafeClientConnManager;
  44 import org.apache.http.params.BasicHttpParams;
  45 import org.apache.http.params.HttpParams;
  46 import org.apache.http.params.HttpProtocolParams;
  47
  48 import javax.imageio.ImageIO;
  49 import javax.mail.Authenticator;
  50 import javax.servlet.ServletConfig;
  51 import javax.servlet.ServletException;
  52 import javax.servlet.http.HttpServlet;
  53 import javax.servlet.http.HttpServletRequest;
  54 import javax.servlet.http.HttpServletResponse;
  55 import java.awt.image.BufferedImage;
  56 import java.io.IOException;
  57 import java.io.InputStream;
  58 import java.io.OutputStreamWriter;
  59 import java.io.Writer;
  60 import java.net.URI;
  61 import java.net.URISyntaxException;
  62 import java.net.UnknownHostException;
  63 import java.util.Hashtable;
  64 import java.util.List;
  65 import java.util.Timer;
  66 import java.util.logging.Logger;
  67
  68 /**
  69  * {@link HttpServlet} which decodes images containing barcodes. Given a URL, it will
  70  * retrieve the image and decode it. It can also process image files uploaded via POST.
  71  *
  72  * @author Sean Owen (srowen@google.com)
  73  */
  74 public final class DecodeServlet extends HttpServlet {
  75
  76   private static final long MAX_IMAGE_SIZE = 500000L;
  77   private static final long EMAIL_CHECK_INTERVAL = 2L * 60 * 1000;
  78
  79   private static final Logger log = Logger.getLogger(DecodeServlet.class.getName());
  80
  81   static final Hashtable<DecodeHintType, Object> HINTS;
  82
  83   static {
  84     HINTS = new Hashtable<DecodeHintType, Object>(3);
  85     HINTS.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
  86   }
  87
  88   private HttpClient client;
  89   private DiskFileItemFactory diskFileItemFactory;
  90   private Timer emailTimer;
  91
  92   @Override
  93   public void init(ServletConfig servletConfig) throws ServletException {
  94
  95     Logger logger = Logger.getLogger("com.google.zxing");
  96     logger.addHandler(new ServletContextLogHandler(servletConfig.getServletContext()));
  97
  98     String emailAddress = servletConfig.getInitParameter("emailAddress");
  99     String emailPassword = servletConfig.getInitParameter("emailPassword");
 100     if (emailAddress == null || emailPassword == null) {
 101       throw new ServletException("emailAddress or emailPassword not specified");
 102     }
 103
 104     HttpParams params = new BasicHttpParams();
 105     HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
 106
 107     SchemeRegistry registry = new SchemeRegistry();
 108     registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
 109     registry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
 110
 111     client = new DefaultHttpClient(new ThreadSafeClientConnManager(params, registry), params);
 112
 113     diskFileItemFactory = new DiskFileItemFactory();
 114
 115     Authenticator emailAuthenticator = new EmailAuthenticator(emailAddress, emailPassword);
 116     emailTimer = new Timer("Email decoder timer", true);
 117     emailTimer.schedule(new DecodeEmailTask(emailAddress, emailAuthenticator), 0L, EMAIL_CHECK_INTERVAL);
 118
 119     log.info("DecodeServlet configured");
 120   }
 121
 122   @Override
 123   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 124
 125     String imageURIString = request.getParameter("u");
 126     if (imageURIString == null || imageURIString.length() == 0) {
 127       response.sendRedirect("badurl.jspx");
 128       return;
 129     }
 130
 131     if (!(imageURIString.startsWith("http://") || imageURIString.startsWith("https://"))) {
 132       imageURIString = "http://" + imageURIString;
 133     }
 134
 135     URI imageURI;
 136     try {
 137       imageURI = new URI(imageURIString);
 138     } catch (URISyntaxException urise) {
 139       response.sendRedirect("badurl.jspx");
 140       return;
 141     }
 142
 143     HttpGet getRequest = new HttpGet(imageURI);
 144
 145     try {
 146       HttpResponse getResponse = client.execute(getRequest);
 147       if (getResponse.getStatusLine().getStatusCode() != HttpServletResponse.SC_OK) {
 148         response.sendRedirect("badurl.jspx");
 149         return;
 150       }
 151       if (!isSizeOK(getResponse)) {
 152         response.sendRedirect("badimage.jspx");
 153         return;
 154       }
 155       log.info("Decoding " + imageURI);
 156       InputStream is = getResponse.getEntity().getContent();
 157       try {
 158         processStream(is, request, response);
 159       } finally {
 160         is.close();
 161       }
 162     } catch (InterruptedException ie) {
 163       getRequest.abort();
 164       response.sendRedirect("badurl.jspx");
 165     } catch (HttpException he) {
 166       getRequest.abort();
 167       response.sendRedirect("badurl.jspx");
 168     } catch (UnknownHostException uhe) {
 169       getRequest.abort();
 170       response.sendRedirect("badurl.jspx");
 171     }
 172
 173   }
 174
 175   @Override
 176   protected void doPost(HttpServletRequest request, HttpServletResponse response)
 177           throws ServletException, IOException {
 178
 179     if (!ServletFileUpload.isMultipartContent(request)) {
 180       response.sendRedirect("badimage.jspx");
 181       return;
 182     }
 183
 184     ServletFileUpload upload = new ServletFileUpload(diskFileItemFactory);
 185     upload.setFileSizeMax(MAX_IMAGE_SIZE);
 186
 187     // Parse the request
 188     try {
 189       for (FileItem item : (List<FileItem>) upload.parseRequest(request)) {
 190         if (!item.isFormField()) {
 191           if (item.getSize() <= MAX_IMAGE_SIZE) {
 192             log.info("Decoding uploaded file");
 193             InputStream is = item.getInputStream();
 194             try {
 195               processStream(is, request, response);
 196             } finally {
 197               is.close();
 198             }
 199           } else {
 200             response.sendRedirect("badimage.jspx");
 201           }
 202           break;
 203         }
 204       }
 205     } catch (FileUploadException fue) {
 206       response.sendRedirect("badimage.jspx");
 207     }
 208
 209   }
 210
 211   private static void processStream(InputStream is, HttpServletRequest request, HttpServletResponse response)
 212       throws ServletException, IOException {
 213     BufferedImage image = ImageIO.read(is);
 214     if (image == null) {
 215       response.sendRedirect("badimage.jspx");
 216       return;
 217     }
 218
 219     Reader reader = new MultiFormatReader();
 220     Result result;
 221     try {
 222       result = reader.decode(new BufferedImageMonochromeBitmapSource(image), HINTS);
 223     } catch (ReaderException re) {
 224       log.info("DECODE FAILED: " + re.toString());
 225       response.sendRedirect("notfound.jspx");
 226       return;
 227     }
 228
 229     if (request.getParameter("full") == null) {
 230       response.setContentType("text/plain");
 231       response.setCharacterEncoding("UTF8");
 232       Writer out = new OutputStreamWriter(response.getOutputStream(), "UTF8");
 233       try {
 234         out.write(result.getText());
 235       } finally {
 236         out.close();
 237       }
 238     } else {
 239       request.setAttribute("result", result);
 240       byte[] rawBytes = result.getRawBytes();
 241       if (rawBytes != null) {
 242         request.setAttribute("rawBytesString", arrayToString(rawBytes));
 243       } else {
 244         request.setAttribute("rawBytesString", "(Not applicable)");
 245       }
 246       ParsedResult parsedResult = ResultParser.parseResult(result);
 247       request.setAttribute("parsedResult", parsedResult);
 248       request.getRequestDispatcher("decoderesult.jspx").forward(request, response);
 249     }
 250   }
 251
 252   private static boolean isSizeOK(HttpMessage getResponse) {
 253     Header lengthHeader = getResponse.getLastHeader("Content-Length");
 254     if (lengthHeader != null) {
 255       long length = Long.parseLong(lengthHeader.getValue());
 256       if (length > MAX_IMAGE_SIZE) {
 257         return false;
 258       }
 259     }
 260     return true;
 261   }
 262
 263   private static String arrayToString(byte[] bytes) {
 264     int length = bytes.length;
 265     StringBuilder result = new StringBuilder(length << 2);
 266     int i = 0;
 267     while (i < length) {
 268       int max = Math.min(i + 8, length);
 269       for (int j = i; j < max; j++) {
 270         int value = bytes[j] & 0xFF;
 271         result.append(Integer.toHexString(value / 16));
 272         result.append(Integer.toHexString(value % 16));
 273         result.append(' ');
 274       }
 275       result.append('\n');
 276       i += 8;
 277     }
 278     for (int j = i - 8; j < length; j++) {
 279       result.append(Integer.toHexString(bytes[j] & 0xFF));
 280       result.append(' ');
 281     }
 282     return result.toString();
 283   }
 284
 285   @Override
 286   public void destroy() {
 287     log.config("DecodeServlet shutting down...");
 288     emailTimer.cancel();
 289   }
 290
 291 }