Java tutorial
/* * Copyright 2014 EUBrazilCC (EU?Brazil Cloud Connect) * * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by * the European Commission - subsequent versions of the EUPL (the "Licence"); * You may not use this work except in compliance with the Licence. * You may obtain a copy of the Licence at: * * http://ec.europa.eu/idabc/eupl * * Unless required by applicable law or agreed to in writing, software * distributed under the Licence is distributed on an "AS IS" basis, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the Licence for the specific language governing permissions and * limitations under the Licence. * * This product combines work with different licenses. See the "NOTICE" text * file for details on the various modules and licenses. * The "NOTICE" text file is part of the distribution. Any derivative works * that you distribute must include a readable copy of the "NOTICE" text file. */ package eu.eubrazilcc.lvl.storage.dao; import static com.google.common.collect.Lists.transform; import static eu.eubrazilcc.lvl.storage.mongodb.MongoDBConnector.MONGODB_CONN; import static eu.eubrazilcc.lvl.storage.mongodb.MongoDBHelper.toProjection; import static eu.eubrazilcc.lvl.storage.mongodb.jackson.MongoDBJsonMapper.JSON_MAPPER; import static org.slf4j.LoggerFactory.getLogger; import java.io.IOException; import java.io.OutputStream; import java.util.List; import javax.annotation.Nullable; import org.apache.commons.lang.mutable.MutableLong; import org.bson.types.ObjectId; import org.slf4j.Logger; import com.fasterxml.jackson.annotation.JsonProperty; import com.fasterxml.jackson.core.JsonProcessingException; import com.fasterxml.jackson.databind.annotation.JsonDeserialize; import com.fasterxml.jackson.databind.annotation.JsonSerialize; import com.google.common.base.Function; import com.google.common.collect.ImmutableMap; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.util.JSON; import eu.eubrazilcc.lvl.core.Notification; import eu.eubrazilcc.lvl.core.Sorting; import eu.eubrazilcc.lvl.core.geojson.Point; import eu.eubrazilcc.lvl.core.geojson.Polygon; import eu.eubrazilcc.lvl.storage.mongodb.jackson.ObjectIdDeserializer; import eu.eubrazilcc.lvl.storage.mongodb.jackson.ObjectIdSerializer; import eu.eubrazilcc.lvl.storage.transform.TransientStore; /** * {@link Notification} DAO. * @author Erik Torres <ertorser@upv.es> */ public enum NotificationDAO implements BaseDAO<String, Notification> { NOTIFICATION_DAO; private final static Logger LOGGER = getLogger(NotificationDAO.class); public static final String COLLECTION = "notifications"; public static final String MORPHIA_KEY = "_id"; public static final String DB_PREFIX = "notification."; public static final String PRIORITY_KEY = DB_PREFIX + "priority"; public static final String ADDRESSE_KEY = DB_PREFIX + "addressee"; public static final String ISSUED_AT_KEY = DB_PREFIX + "issuedAt"; private NotificationDAO() { MONGODB_CONN.createNonUniqueIndex(PRIORITY_KEY, COLLECTION, false); MONGODB_CONN.createNonUniqueIndex(ADDRESSE_KEY, COLLECTION, false); MONGODB_CONN.createNonUniqueIndex(ISSUED_AT_KEY, COLLECTION, false); } @Override public WriteResult<Notification> insert(final Notification notification) { // remove transient fields from the element before saving it to the database final NotificationTransientStore store = NotificationTransientStore.start(notification); final DBObject obj = map(store); final String id = MONGODB_CONN.insert(obj, COLLECTION); // restore transient fields store.restore(); return new WriteResult.Builder<Notification>().id(id).build(); } @Override public WriteResult<Notification> insert(final Notification notification, final boolean ignoreDuplicates) { throw new UnsupportedOperationException( "Inserting ignoring duplicates is not currently supported in this class"); } @Override public Notification update(final Notification notification) { // remove transient fields from the element before saving it to the database final NotificationTransientStore store = NotificationTransientStore.start(notification); final DBObject obj = map(store); MONGODB_CONN.update(obj, key(store.getId()), COLLECTION); // restore transient fields store.restore(); return null; } @Override public void delete(final String id) { MONGODB_CONN.remove(key(id), COLLECTION); } @Override public List<Notification> findAll() { return list(0, Integer.MAX_VALUE, null, null, null, null); } @Override public Notification find(final String id) { final BasicDBObject obj = MONGODB_CONN.get(key(id), COLLECTION); return parseBasicDBObjectOrNull(obj); } @Override public List<Notification> list(final int start, final int size, final @Nullable ImmutableMap<String, String> filter, final @Nullable Sorting sorting, final @Nullable ImmutableMap<String, Boolean> projection, final @Nullable MutableLong count) { // execute the query in the database (unsupported filter) return transform( MONGODB_CONN.list(sortCriteria(), COLLECTION, start, size, null, toProjection(projection), count), new Function<BasicDBObject, Notification>() { @Override public Notification apply(final BasicDBObject obj) { return parseBasicDBObject(obj); } }); } @Override public long count() { return MONGODB_CONN.count(COLLECTION); } @Override public List<Notification> getNear(final Point point, final double maxDistance) { throw new UnsupportedOperationException("Geospatial searches are not currently supported in this class"); } @Override public List<Notification> geoWithin(final Polygon polygon) { throw new UnsupportedOperationException("Geospatial searches are not currently supported in this class"); } @Override public void stats(final OutputStream os) throws IOException { MONGODB_CONN.stats(os, COLLECTION); } private BasicDBObject key(final String id) { return new BasicDBObject(MORPHIA_KEY, new ObjectId(id)); } private BasicDBObject sortCriteria() { return new BasicDBObject(MORPHIA_KEY, 1); } private Notification parseBasicDBObject(final BasicDBObject obj) { final NotificationEntity entity = map(obj); final Notification notification = entity.getNotification(); notification.setId(entity.getId().toHexString()); return notification; } private Notification parseBasicDBObjectOrNull(final BasicDBObject obj) { Notification notification = null; if (obj != null) { final NotificationEntity entity = map(obj); if (entity != null) { notification = entity.getNotification(); notification.setId(entity.getId().toHexString()); } } return notification; } private DBObject map(final NotificationTransientStore store) { DBObject obj = null; try { obj = (DBObject) JSON.parse(JSON_MAPPER.writeValueAsString(new NotificationEntity(store.purge()))); } catch (JsonProcessingException e) { LOGGER.error("Failed to write notification to DB object", e); } return obj; } private NotificationEntity map(final BasicDBObject obj) { NotificationEntity entity = null; try { entity = JSON_MAPPER.readValue(obj.toString(), NotificationEntity.class); } catch (IOException e) { LOGGER.error("Failed to read notification from DB object", e); } return entity; } /** * Extracts from an entity the fields that depends on the service (e.g. links) * before storing the entity in the database. These fields are stored in this * class and can be reinserted later in the entity. * @author Erik Torres <ertorser@upv.es> */ public static class NotificationTransientStore extends TransientStore<Notification> { private String id; public NotificationTransientStore(final Notification notification) { super(notification); } public String getId() { return id; } public Notification purge() { id = element.getId(); element.setId(null); return element; } public Notification restore() { element.setId(id); return element; } public static NotificationTransientStore start(final Notification notification) { return new NotificationTransientStore(notification); } } /** * Notification entity. * @author Erik Torres <ertorser@upv.es> */ public static class NotificationEntity { @JsonSerialize(using = ObjectIdSerializer.class) @JsonDeserialize(using = ObjectIdDeserializer.class) @JsonProperty("_id") private ObjectId id; private Notification notification; public NotificationEntity() { } public NotificationEntity(final Notification notification) { setNotification(notification); } public ObjectId getId() { return id; } public void setId(final ObjectId id) { this.id = id; } public Notification getNotification() { return notification; } public void setNotification(final Notification notification) { this.notification = notification; } } }