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