bayesiananalysis.java

java mail,java mailjava mailjava mailjava mail

        try {
            analyzer.initSqlQueries(datasource.getConnection(), getMailetContext());
        } catch (Exception e) {
            throw new MessagingException("Exception initializing queries", e);
        }        
        
        try {
            loadData(datasource.getConnection());
        } catch (java.sql.SQLException se) {
            throw new MessagingException("SQLException loading data", se);
        }        
    }
    
    /**
     * Scans the mail and determines the spam probability.
     *
     * @param mail The Mail message to be scanned.
     * @throws MessagingException if a problem arises
     */
    public void service(Mail mail) throws MessagingException {
        
        try {
            MimeMessage message = mail.getMessage();
            
            if (ignoreLocalSender) {
                // ignore the message if the sender is local
                if (mail.getSender() != null
                        && getMailetContext().isLocalServer(mail.getSender().getHost())) {
                    return;
                }
            }
            
            String [] headerArray = message.getHeader(headerName);
            // ignore the message if already analyzed
            if (headerArray != null && headerArray.length > 0) {
                return;
            }
            
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            
            double probability;
            
            if (message.getSize() < getMaxSize()) {
                message.writeTo(baos);
                probability = analyzer.computeSpamProbability(new BufferedReader(new StringReader(baos.toString())));
            } else {
                probability = 0.0;
            }
            
            mail.setAttribute(MAIL_ATTRIBUTE_NAME, new Double(probability));
            message.setHeader(headerName, Double.toString(probability));
            
            DecimalFormat probabilityForm = (DecimalFormat) DecimalFormat.getInstance();
            probabilityForm.applyPattern("##0.##%");
            String probabilityString = probabilityForm.format(probability);
            
            String senderString;
            if (mail.getSender() == null) {
                senderString = "null";
            } else {
                senderString = mail.getSender().toString();
            }
            if (probability > 0.1) {
                log(headerName
                        + ": "
                        + probabilityString
                        + "; From: "
                        + senderString
                        + "; Recipient(s): "
                        + getAddressesString(mail.getRecipients()));
                
                appendToSubject(message,
                        " [" + probabilityString
                        + (probability > 0.9 ? " SPAM" : " spam") + "]");
            }
            
            saveChanges(message);
            
        } catch (Exception e) {
            log("Exception: "
                    + e.getMessage(), e);
            throw new MessagingException("Exception thrown", e);
        }
    }
    
    private void loadData(Connection conn)
    throws java.sql.SQLException {
        
        try {
            // this is synchronized to avoid concurrent update of the corpus
            synchronized(JDBCBayesianAnalyzer.DATABASE_LOCK) {
                analyzer.tokenCountsClear();
                analyzer.loadHamNSpam(conn);
                analyzer.buildCorpus();
                analyzer.tokenCountsClear();
            }
            
            log("BayesianAnalysis Corpus loaded");
            
            touchLastCorpusLoadTime();
            
        } finally {
            if (conn != null) {
                theJDBCUtil.closeJDBCConnection(conn);
            }
        }
        
    }
    
    private String getAddressesString(Collection addresses) {
        if (addresses == null) {
            return "null";
        }
        
        Iterator iter = addresses.iterator();
        StringBuffer sb = new StringBuffer();
        sb.append('[');
        for (int i = 0; iter.hasNext(); i++) {
            sb.append(iter.next());
            if (i + 1 < addresses.size()) {
                sb.append(", ");
            }
        }
        sb.append(']');
        return sb.toString();
    }
    
    private void appendToSubject(MimeMessage message, String toAppend) {
        try {
            String subject = message.getSubject();
            
            if (subject == null) {
                message.setSubject(toAppend, "iso-8859-1");
            } else {
                message.setSubject(toAppend + " " + subject, "iso-8859-1");
            }
        } catch (MessagingException ex) {}
    }
    
    private void sendReplyFromPostmaster(Mail mail, String stringContent) throws MessagingException {
        try {
            MailAddress notifier = getMailetContext().getPostmaster();
            
            MailAddress senderMailAddress = mail.getSender();
            
            MimeMessage message = mail.getMessage();
            //Create the reply message
            MimeMessage reply = new MimeMessage(Session.getDefaultInstance(System.getProperties(), null));
            
            //Create the list of recipients in the Address[] format
            InternetAddress[] rcptAddr = new InternetAddress[1];
            rcptAddr[0] = senderMailAddress.toInternetAddress();
            reply.setRecipients(Message.RecipientType.TO, rcptAddr);
            
            //Set the sender...
            reply.setFrom(notifier.toInternetAddress());
            
            //Create the message body
            MimeMultipart multipart = new MimeMultipart();
            //Add message as the first mime body part
            MimeBodyPart part = new MimeBodyPart();
            part.setContent(stringContent, "text/plain");
            part.setHeader(RFC2822Headers.CONTENT_TYPE, "text/plain");
            multipart.addBodyPart(part);
            
            reply.setContent(multipart);
            reply.setHeader(RFC2822Headers.CONTENT_TYPE, multipart.getContentType());
            
            //Create the list of recipients in our MailAddress format
            Set recipients = new HashSet();
            recipients.add(senderMailAddress);
            
            //Set additional headers
            if (reply.getHeader(RFC2822Headers.DATE)==null){
                reply.setHeader(RFC2822Headers.DATE, rfc822DateFormat.format(new java.util.Date()));
            }
            String subject = message.getSubject();
            if (subject == null) {
                subject = "";
            }
            if (subject.indexOf("Re:") == 0){
                reply.setSubject(subject);
            } else {
                reply.setSubject("Re:" + subject);
            }
            reply.setHeader(RFC2822Headers.IN_REPLY_TO, message.getMessageID());
            
            //Send it off...
            getMailetContext().sendMail(notifier, recipients, reply);
        } catch (Exception e) {
            log("Exception found sending reply", e);
        }
    }
    
    /**
     * Saves changes resetting the original message id.
     */
    private void saveChanges(MimeMessage message) throws MessagingException {
        String messageId = message.getMessageID();
        message.saveChanges();
        if (messageId != null) {
            message.setHeader(RFC2822Headers.MESSAGE_ID, messageId);
        }
    }

    private static class CorpusLoader extends Thread {
        
        private BayesianAnalysis analysis;
        
        private CorpusLoader(BayesianAnalysis analysis) {
            super("BayesianAnalysis Corpus Loader");
            this.analysis = analysis;
        }
        
        /** Thread entry point.
         */
        public void run() {
        analysis.log("CorpusLoader thread started: will wake up every " + CORPUS_RELOAD_INTERVAL + " ms");
        
        try {
            Thread.sleep(CORPUS_RELOAD_INTERVAL);

            while (true) {
                if (analysis.getLastCorpusLoadTime() < JDBCBayesianAnalyzer.getLastDatabaseUpdateTime()) {
                    analysis.log("Reloading Corpus ...");
                    try {
                        analysis.loadData(analysis.datasource.getConnection());
                        analysis.log("Corpus reloaded");
                    } catch (java.sql.SQLException se) {
                        analysis.log("SQLException: ", se);
                    }
                    
                }
                
                if (Thread.interrupted()) {
                    break;
                }
                Thread.sleep(CORPUS_RELOAD_INTERVAL);
            }
        }
        catch (InterruptedException ex) {
            interrupt();
        }
        }
        
    }
    
}