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.newArrayList; 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 eu.eubrazilcc.lvl.storage.transform.SameTransientStore.startStore; 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.BasicDBList; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.util.JSON; import eu.eubrazilcc.lvl.core.LvlInstance; 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.MongoDBDuplicateKeyException; import eu.eubrazilcc.lvl.storage.mongodb.jackson.ObjectIdDeserializer; import eu.eubrazilcc.lvl.storage.mongodb.jackson.ObjectIdSerializer; import eu.eubrazilcc.lvl.storage.transform.SameTransientStore; /** * {@link LvlInstance} DAO. * @author Erik Torres <ertorser@upv.es> */ public enum LvlInstanceDAO implements BaseDAO<String, LvlInstance> { INSTANCE_DAO; private final static Logger LOGGER = getLogger(LvlInstanceDAO.class); public static final String COLLECTION = "lvl_instances"; public static final String DB_PREFIX = "lvlInstance."; public static final String PRIMARY_KEY = DB_PREFIX + "instanceId"; public static final String GEOLOCATION_KEY = DB_PREFIX + "location"; private LvlInstanceDAO() { MONGODB_CONN.createIndex(PRIMARY_KEY, COLLECTION); MONGODB_CONN.createGeospatialIndex(GEOLOCATION_KEY, COLLECTION); } @Override public WriteResult<LvlInstance> insert(final LvlInstance instance) { return insert(instance, false); } @Override public WriteResult<LvlInstance> insert(final LvlInstance instance, final boolean ignoreDuplicates) { // remove transient fields from the element before saving it to the database final SameTransientStore<LvlInstance> store = startStore(instance); final DBObject obj = map(store); String id = null; try { id = MONGODB_CONN.insert(obj, COLLECTION); } catch (MongoDBDuplicateKeyException dke) { if (ignoreDuplicates) { final BasicDBObject duplicate = MONGODB_CONN.get(key(instance.getInstanceId()), COLLECTION); id = entity2ObjectId(duplicate); } else { // re-throw exception throw dke; } } // restore transient fields store.restore(); return new WriteResult.Builder<LvlInstance>().id(id).build(); } @Override public LvlInstance update(final LvlInstance instance) { // remove transient fields from the element before saving it to the database final SameTransientStore<LvlInstance> store = startStore(instance); final DBObject obj = map(store); MONGODB_CONN.update(obj, key(instance.getInstanceId()), COLLECTION); // restore transient fields store.restore(); return null; } @Override public void delete(final String pmid) { MONGODB_CONN.remove(key(pmid), COLLECTION); } @Override public List<LvlInstance> findAll() { return list(0, Integer.MAX_VALUE, null, null, null, null); } @Override public LvlInstance find(final String pmid) { final BasicDBObject obj = MONGODB_CONN.get(key(pmid), COLLECTION); return parseBasicDBObjectOrNull(obj); } @Override public List<LvlInstance> 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, LvlInstance>() { @Override public LvlInstance apply(final BasicDBObject obj) { return parseBasicDBObject(obj); } }); } @Override public long count() { return MONGODB_CONN.count(COLLECTION); } @Override public List<LvlInstance> getNear(final Point point, final double maxDistance) { final List<LvlInstance> instances = newArrayList(); final BasicDBList list = MONGODB_CONN.geoNear(COLLECTION, point.getCoordinates().getLongitude(), point.getCoordinates().getLatitude(), maxDistance); for (int i = 0; i < list.size(); i++) { instances.add(parseObject(list.get(i))); } return instances; } @Override public List<LvlInstance> geoWithin(final Polygon polygon) { return transform(MONGODB_CONN.geoWithin(GEOLOCATION_KEY, COLLECTION, polygon), new Function<BasicDBObject, LvlInstance>() { @Override public LvlInstance apply(final BasicDBObject obj) { return parseBasicDBObject(obj); } }); } @Override public void stats(final OutputStream os) throws IOException { MONGODB_CONN.stats(os, COLLECTION); } private BasicDBObject key(final String key) { return new BasicDBObject(PRIMARY_KEY, key); } private BasicDBObject sortCriteria() { return new BasicDBObject(PRIMARY_KEY, 1); } private LvlInstance parseBasicDBObject(final BasicDBObject obj) { return map(obj).getLvlInstance(); } private LvlInstance parseBasicDBObjectOrNull(final BasicDBObject obj) { LvlInstance instance = null; if (obj != null) { final LvlInstanceEntity entity = map(obj); if (entity != null) { instance = entity.getLvlInstance(); } } return instance; } private String entity2ObjectId(final BasicDBObject obj) { return map(obj).getId().toString(); } private LvlInstance parseObject(final Object obj) { final BasicDBObject obj2 = (BasicDBObject) obj; return map((BasicDBObject) obj2.get("obj")).getLvlInstance(); } private DBObject map(final SameTransientStore<LvlInstance> store) { DBObject obj = null; try { obj = (DBObject) JSON.parse(JSON_MAPPER.writeValueAsString(new LvlInstanceEntity(store.purge()))); } catch (JsonProcessingException e) { LOGGER.error("Failed to write instance to DB object", e); } return obj; } private LvlInstanceEntity map(final BasicDBObject obj) { LvlInstanceEntity entity = null; try { entity = JSON_MAPPER.readValue(obj.toString(), LvlInstanceEntity.class); } catch (IOException e) { LOGGER.error("Failed to read instance from DB object", e); } return entity; } /** * LvlInstance entity. * @author Erik Torres <ertorser@upv.es> */ public static class LvlInstanceEntity { @JsonSerialize(using = ObjectIdSerializer.class) @JsonDeserialize(using = ObjectIdDeserializer.class) @JsonProperty("_id") private ObjectId id; private LvlInstance instance; public LvlInstanceEntity() { } public LvlInstanceEntity(final LvlInstance instance) { setLvlInstance(instance); } public ObjectId getId() { return id; } public void setId(final ObjectId id) { this.id = id; } public LvlInstance getLvlInstance() { return instance; } public void setLvlInstance(final LvlInstance instance) { this.instance = instance; } } }