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.util.Hashtable;
  62 import java.util.List;
  63 import java.util.Timer;
  64 import java.util.logging.Logger;
  65
  66 /**
  67  * {@link HttpServlet} which decodes images containing barcodes. Given a URL, it will
  68  * retrieve the image and decode it. It can also process image files uploaded via POST.
  69  *
  70  * @author Sean Owen (srowen@google.com)
  71  */
  72 public final class DecodeServlet extends HttpServlet {
  73
  74   private static final long MAX_IMAGE_SIZE = 500000L;
  75   private static final long EMAIL_CHECK_INTERVAL = 60000L;
  76
  77   private static final Logger log = Logger.getLogger(DecodeServlet.class.getName());
  78
  79   static final Hashtable<DecodeHintType, Object> HINTS;
  80
  81   static {
  82     HINTS = new Hashtable<DecodeHintType, Object>(3);
  83     HINTS.put(DecodeHintType.TRY_HARDER, Boolean.TRUE);
  84   }
  85
  86   private HttpClient client;
  87   private DiskFileItemFactory diskFileItemFactory;
  88   private Timer emailTimer;
  89
  90   @Override
  91   public void init(ServletConfig servletConfig) throws ServletException {
  92
  93     Logger logger = Logger.getLogger("com.google.zxing");
  94     logger.addHandler(new ServletContextLogHandler(servletConfig.getServletContext()));
  95
  96     String emailAddress = servletConfig.getInitParameter("emailAddress");
  97     String emailPassword = servletConfig.getInitParameter("emailPassword");
  98     if (emailAddress == null || emailPassword == null) {
  99       throw new ServletException("emailAddress or emailPassword not specified");
 100     }
 101
 102     HttpParams params = new BasicHttpParams();
 103     HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
 104
 105     SchemeRegistry registry = new SchemeRegistry();
 106     registry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
 107     registry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
 108
 109     client = new DefaultHttpClient(new ThreadSafeClientConnManager(params, registry), params);
 110
 111     diskFileItemFactory = new DiskFileItemFactory();
 112
 113     Authenticator emailAuthenticator = new EmailAuthenticator(emailAddress, emailPassword);
 114     emailTimer = new Timer("Email decoder timer", true);
 115     emailTimer.schedule(new DecodeEmailTask(emailAddress, emailAuthenticator), 0L, EMAIL_CHECK_INTERVAL);
 116
 117     log.info("DecodeServlet configured");
 118   }
 119
 120   @Override
 121   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 122
 123     String imageURIString = request.getParameter("u");
 124     if (imageURIString == null || imageURIString.length() == 0) {
 125       response.sendRedirect("badurl.jspx");
 126       return;
 127     }
 128
 129     if (!(imageURIString.startsWith("http://") || imageURIString.startsWith("https://"))) {
 130       imageURIString = "http://" + imageURIString;
 131     }
 132
 133     URI imageURI;
 134     try {
 135       imageURI = new URI(imageURIString);
 136     } catch (URISyntaxException urise) {
 137       response.sendRedirect("badurl.jspx");
 138       return;
 139     }
 140
 141     HttpGet getRequest = new HttpGet(imageURI);
 142
 143     try {
 144       HttpResponse getResponse = client.execute(getRequest);
 145       if (getResponse.getStatusLine().getStatusCode() != HttpServletResponse.SC_OK) {
 146         response.sendRedirect("badurl.jspx");
 147         return;
 148       }
 149       if (!isSizeOK(getResponse)) {
 150         response.sendRedirect("badimage.jspx");
 151         return;
 152       }
 153       log.info("Decoding " + imageURI);
 154       InputStream is = getResponse.getEntity().getContent();
 155       try {
 156         processStream(is, request, response);
 157       } finally {
 158         is.close();
 159       }
 160     } catch (InterruptedException ie) {
 161       getRequest.abort();
 162       response.sendRedirect("badurl.jspx");
 163     } catch (HttpException he) {
 164       getRequest.abort();
 165       response.sendRedirect("badurl.jspx");
 166     }
 167
 168   }
 169
 170   @Override
 171   protected void doPost(HttpServletRequest request, HttpServletResponse response)
 172           throws ServletException, IOException {
 173
 174     if (!ServletFileUpload.isMultipartContent(request)) {
 175       response.sendRedirect("badimage.jspx");
 176       return;
 177     }
 178
 179     ServletFileUpload upload = new ServletFileUpload(diskFileItemFactory);
 180     upload.setFileSizeMax(MAX_IMAGE_SIZE);
 181
 182     // Parse the request
 183     try {
 184       for (FileItem item : (List<FileItem>) upload.parseRequest(request)) {
 185         if (!item.isFormField()) {
 186           if (item.getSize() <= MAX_IMAGE_SIZE) {
 187             log.info("Decoding uploaded file");
 188             InputStream is = item.getInputStream();
 189             try {
 190               processStream(is, request, response);
 191             } finally {
 192               is.close();
 193             }
 194           } else {
 195             response.sendRedirect("badimage.jspx");
 196           }
 197           break;
 198         }
 199       }
 200     } catch (FileUploadException fue) {
 201       response.sendRedirect("badimage.jspx");
 202     }
 203
 204   }
 205
 206   private static void processStream(InputStream is, HttpServletRequest request, HttpServletResponse response)
 207       throws ServletException, IOException {
 208     BufferedImage image = ImageIO.read(is);
 209     if (image == null) {
 210       response.sendRedirect("badimage.jspx");
 211       return;
 212     }
 213
 214     Reader reader = new MultiFormatReader();
 215     Result result;
 216     try {
 217       result = reader.decode(new BufferedImageMonochromeBitmapSource(image), HINTS);
 218     } catch (ReaderException re) {
 219       log.info("DECODE FAILED: " + re.toString());
 220       response.sendRedirect("notfound.jspx");
 221       return;
 222     }
 223
 224     if (request.getParameter("full") == null) {
 225       response.setContentType("text/plain");
 226       response.setCharacterEncoding("UTF-8");
 227       Writer out = new OutputStreamWriter(response.getOutputStream(), "UTF-8");
 228       try {
 229         out.write(result.getText());
 230       } finally {
 231         out.close();
 232       }
 233     } else {
 234       request.setAttribute("result", result);
 235       ParsedReaderResult parsedReaderResult = ParsedReaderResult.parseReaderResult(result);
 236       request.setAttribute("parsedReaderResult", parsedReaderResult);
 237       request.getRequestDispatcher("decoderesult.jspx").forward(request, response);
 238     }
 239   }
 240
 241   private static boolean isSizeOK(HttpMessage getResponse) {
 242     Header lengthHeader = getResponse.getLastHeader("Content-Length");
 243     if (lengthHeader != null) {
 244       long length = Long.parseLong(lengthHeader.getValue());
 245       if (length > MAX_IMAGE_SIZE) {
 246         return false;
 247       }
 248     }
 249     return true;
 250   }
 251
 252   @Override
 253   public void destroy() {
 254     log.config("DecodeServlet shutting down...");
 255     emailTimer.cancel();
 256   }
 257
 258 }