Java tutorial
/* Copyright (c) 2011 Danish Maritime Authority * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 3 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this library. If not, see <http://www.gnu.org/licenses/>. */ package dk.dma.ais.abnormal.event.db.jpa; import com.google.inject.Inject; import dk.dma.ais.abnormal.event.db.EventRepository; import dk.dma.ais.abnormal.event.db.domain.Event; import org.apache.commons.lang.StringUtils; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.util.Date; import java.util.List; import static java.lang.System.currentTimeMillis; /** * JpaEventRepository is an implementation of the EventRepository interface which * manages persistent Event objects in a relational database accessed via Hibernate. */ @SuppressWarnings("JpaQlInspection") public class JpaEventRepository implements EventRepository { private static final Logger LOG = LoggerFactory.getLogger(JpaEventRepository.class); { LOG.info(this.getClass().getSimpleName() + " created (" + this + ")."); } private final SessionFactory sessionFactory; private final boolean readonly; @Inject public JpaEventRepository(SessionFactory sessionFactory, boolean readonly) { this.readonly = readonly; this.sessionFactory = sessionFactory; } private Session getSession() { Session session = sessionFactory.openSession(); LOG.debug("Database session acquired: " + session); if (readonly) { session.setDefaultReadOnly(true); } return session; } @Override public List<String> getEventTypes() { Session session = getSession(); List events = null; try { Query query = session .createQuery("SELECT DISTINCT e.class AS c FROM Event e WHERE e.suppressed=false ORDER BY c"); events = query.list(); } finally { session.close(); LOG.debug("Database session closed: " + session); } return events; } @Override public void save(Event event) { Session session = getSession(); try { session.beginTransaction(); session.saveOrUpdate(event); session.getTransaction().commit(); } finally { session.close(); LOG.debug("Database session closed: " + session); } } @Override public Event getEvent(long eventId) { Event event; Session session = getSession(); try { event = (Event) session.get(Event.class, eventId); } finally { session.close(); LOG.debug("Database session closed: " + session); } return event; } @Override public List<Event> findEventsByFromAndToAndTypeAndVesselAndArea(Date from, Date to, String type, String vessel, Double north, Double east, Double south, Double west) { Session session = getSession(); boolean usesFrom = false, usesTo = false, usesType = false, usesVessel = false, usesArea = false; List events = null; try { StringBuilder hql = new StringBuilder(); hql.append("SELECT DISTINCT e FROM Event e "); if (!StringUtils.isBlank(vessel)) { hql.append("LEFT JOIN e.behaviours AS b "); } if (north != null && east != null && south != null && west != null) { hql.append( "LEFT JOIN e.behaviours AS b LEFT JOIN b.trackingPoints AS tp WHERE e.suppressed=false AND latitude<:north AND latitude>:south AND longitude<:east AND longitude>:west AND "); usesArea = true; } else { hql.append("WHERE e.suppressed=false AND "); } // from if (from != null) { hql.append("(e.startTime >= :from OR e.endTime >= :from) AND "); usesFrom = true; } // to if (to != null) { hql.append("(e.startTime <= :to OR e.endTime <= :to) AND "); usesTo = true; } // type if (!StringUtils.isBlank(type)) { hql.append("TYPE(e) IN (:classes) AND "); usesType = true; } // vessel if (!StringUtils.isBlank(vessel)) { hql.append("("); hql.append("b.vessel.callsign LIKE :vessel OR "); hql.append("b.vessel.name LIKE :vessel OR "); try { Long vesselAsLong = Long.valueOf(vessel); hql.append("b.vessel.mmsi = :vessel OR "); hql.append("b.vessel.imo = :vessel OR "); } catch (NumberFormatException e) { } hql.replace(hql.length() - 3, hql.length(), ")"); // "OR " -> ")" if (!vessel.startsWith("%")) { vessel = "%" + vessel; } if (!vessel.endsWith("%")) { vessel = vessel + "%"; } usesVessel = true; } // String hqlAsString = hql.toString().trim(); if (hqlAsString.endsWith("AND")) { hqlAsString = hqlAsString.substring(0, hqlAsString.lastIndexOf("AND")); } // Query query = session.createQuery(hqlAsString); if (usesArea) { query.setParameter("north", north); query.setParameter("east", east); query.setParameter("south", south); query.setParameter("west", west); } if (usesFrom) { query.setParameter("from", from); } if (usesTo) { query.setParameter("to", to); } if (usesType) { String className = "dk.dma.ais.abnormal.event.db.domain." + type; try { Class clazz = Class.forName(className); query.setParameter("classes", clazz); } catch (ClassNotFoundException e) { throw new IllegalArgumentException("Class " + className + " not found."); } } if (usesVessel) { query.setParameter("vessel", vessel); } LOG.debug("Query: " + query.toString()); final long t0 = currentTimeMillis(); events = query.list(); final long t1 = currentTimeMillis(); LOG.debug("Found " + events.size() + " matching events in " + (t1 - t0) + " msecs."); } finally { session.close(); LOG.debug("Database session closed: " + session); } return events; } @Override public List<Event> findEventsByFromAndTo(Date from, Date to) { LOG.debug("Searching events from " + from + " to " + to + "."); Session session = getSession(); List events = null; try { StringBuilder hql = new StringBuilder(); hql.append("SELECT e FROM Event e WHERE "); hql.append("(e.suppressed=false AND e.startTime >= :from AND e.startTime <= :to) OR "); hql.append("(e.suppressed=false AND e.endTime >= :from AND e.endTime <= :to) "); hql.append("ORDER BY e.startTime"); Query query = session.createQuery(hql.toString()); query.setParameter("from", from); query.setParameter("to", to); events = query.list(); } finally { session.close(); LOG.debug("Database session closed: " + session); } LOG.debug("Found " + events.size() + " matching events."); return events; } @Override public List<Event> findRecentEvents(int numberOfEvents) { Session session = getSession(); List events = null; try { Query query = session .createQuery("SELECT e FROM Event e WHERE e.suppressed=false ORDER BY e.startTime DESC"); query.setMaxResults(numberOfEvents); events = query.list(); } finally { session.close(); LOG.debug("Database session closed: " + session); } return events; } @Override public <T extends Event> T findOngoingEventByVessel(int mmsi, Class<T> eventClass) { Session session = getSession(); T event = null; try { Query query = session.createQuery( "SELECT e FROM Event e LEFT JOIN e.behaviours b WHERE TYPE(e) = :clazz AND e.state = :state AND b.vessel.mmsi = :mmsi AND e.suppressed=false"); query.setCacheable(true); query.setParameter("clazz", eventClass); query.setString("state", "ONGOING"); query.setInteger("mmsi", mmsi); List events = query.list(); if (events.size() > 0) { if (events.size() > 1) { LOG.warn("More than one (" + events.size() + ") ongoing event of type " + eventClass + "; expected max. 1. Using first."); } event = (T) events.get(0); } } finally { session.close(); LOG.debug("Database session closed: " + session); } return event; } }