Java tutorial
/* * Computoser is a music-composition algorithm and a website to present the results * Copyright (C) 2012-2014 Bozhidar Bozhanov * * Computoser is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as * published by the Free Software Foundation, either version 3 of the * License, or (at your option) any later version. * * Computoser 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with Computoser. If not, see <http://www.gnu.org/licenses/>. */ package com.music.scheduled; import java.util.ArrayList; import java.util.Collections; import java.util.List; import java.util.Map; import javax.annotation.PostConstruct; import javax.inject.Inject; import org.apache.commons.lang3.SerializationUtils; import org.apache.commons.lang3.StringUtils; import org.joda.time.DateTime; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Value; import org.springframework.scheduling.annotation.Async; import org.springframework.scheduling.annotation.Scheduled; import org.springframework.stereotype.Component; import org.springframework.transaction.annotation.Transactional; import com.google.common.collect.Maps; import com.music.dao.PageableOperation; import com.music.dao.PieceDao; import com.music.dao.UserDao; import com.music.model.persistent.Piece; import com.music.model.persistent.User; import com.music.service.EmailService; import com.music.service.EmailService.EmailDetails; import com.music.util.SecurityUtils; @Component public class PieceDigestSendingJob { private static final Logger logger = LoggerFactory.getLogger(PieceDigestSendingJob.class); @Inject private PieceDao pieceDao; @Inject private UserDao userDao; @Inject private EmailService emailService; @Value("${information.email.sender}") private String from; @Value("${hmac.key}") private String hmacKey; @PostConstruct public void init() { logger.info("Digest job initialized"); } @Scheduled(cron = "0 0 9 ? * 1,4") @Transactional(readOnly = true) public void sendPieceDigestEmails() { logger.info("Sending email digests started"); DateTime now = new DateTime(); DateTime minusTwoDays = now.minusDays(2); List<Piece> pieces = pieceDao.getPiecesInRange(minusTwoDays, now); Collections.shuffle(pieces); final List<Piece> includedPieces = new ArrayList<>(pieces.subList(0, Math.min(pieces.size(), 3))); if (includedPieces.isEmpty()) { return; } // for now - using the same data for all users. TODO send personalized selection final EmailDetails baseDetails = new EmailDetails(); baseDetails.setMessageTemplate("digest.vm"); baseDetails.setSubject("Computoser-generated tracks digest for you"); Map<String, Object> model = Maps.newHashMap(); baseDetails.setMessageTemplateModel(model); baseDetails.setFrom(from); baseDetails.setHtml(true); userDao.performBatched(User.class, 100, new PageableOperation<User>() { @Override public void execute() { for (User user : getData()) { if (user.isReceiveDailyDigest() && StringUtils.isNotBlank(user.getEmail())) { EmailDetails email = SerializationUtils.clone(baseDetails); email.setTo(user.getEmail()); email.setCurrentUser(user); String hmac = SecurityUtils.hmac(user.getEmail(), hmacKey); email.getMessageTemplateModel().put("pieces", includedPieces); email.getMessageTemplateModel().put("hmac", hmac); // needed due to SES restrictions try { Thread.sleep(500); } catch (InterruptedException e) { throw new IllegalStateException(e); } emailService.send(email); } } } }); } @Transactional(readOnly = true) @Async public void sendEmails() { try { sendPieceDigestEmails(); } catch (Exception ex) { logger.warn("Problem sending emails", ex); } } }