com.angstoverseer.service.mail.MailServiceImpl.java Source code

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Here is the source code for com.angstoverseer.service.mail.MailServiceImpl.java

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/* 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.angstoverseer.service.mail;

import com.angstoverseer.service.command.CommandService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import java.io.*;
import java.util.Properties;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

@Component
public class MailServiceImpl implements MailService {

    @Autowired
    private CommandService commandService;

    @Override
    public void handleIncomingEmail(InputStream inputStream) {
        Properties props = new Properties();
        Session session = Session.getDefaultInstance(props, null);

        try {
            MimeMessage mimeMessage = new MimeMessage(session, inputStream);

            Object messageContent = mimeMessage.getContent();
            String message;
            if (messageContent instanceof Multipart) {
                Multipart mp = (Multipart) messageContent;
                BodyPart bodyPart = mp.getBodyPart(0);
                InputStream is = bodyPart.getInputStream();
                message = convertStreamToString(is);
            } else {
                message = (String) messageContent;
            }

            Address sender = mimeMessage.getFrom()[0];
            final String commandOutput = commandService.process(message, extractEmail(sender.toString()));

            sendResponseMail(sender, commandOutput, mimeMessage.getSubject());
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    String extractEmail(String sender) {
        Pattern pattern = Pattern
                .compile("[_A-Za-z0-9-]+(\\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})");
        Matcher matcher = pattern.matcher(sender);
        if (!matcher.find()) {
            throw new RuntimeException("No valid e-mail could be found: " + sender);
        }

        return matcher.group(0);
    }

    private String convertStreamToString(final InputStream is) {
        if (is != null) {
            StringBuilder sb = new StringBuilder();
            String line;

            try {
                BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
                while ((line = reader.readLine()) != null) {
                    sb.append(line).append("\n");
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            } finally {
                try {
                    is.close();
                } catch (Exception e) {
                    throw new RuntimeException(e);
                }
            }
            return sb.toString();
        } else {
            return "";
        }
    }

    private void sendResponseMail(final Address sender, final String answer, final String subject)
            throws Exception {
        Properties props = new Properties();
        Session session = Session.getDefaultInstance(props, null);

        Message mimeMessage = new MimeMessage(session);
        mimeMessage.setFrom(new InternetAddress("overseer@thenewoverseer.appspotmail.com", "Overseer"));
        mimeMessage.addRecipient(Message.RecipientType.TO, new InternetAddress(sender.toString()));
        mimeMessage.setSubject("Re: " + subject);
        mimeMessage.setText(answer);
        Transport.send(mimeMessage);
    }
}