Java tutorial
package org.apache.rya.indexing.mongodb.temporal; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ import static org.apache.rya.indexing.mongodb.temporal.TemporalMongoDBStorageStrategy.INSTANT; import static org.apache.rya.indexing.mongodb.temporal.TemporalMongoDBStorageStrategy.INTERVAL_END; import static org.apache.rya.indexing.mongodb.temporal.TemporalMongoDBStorageStrategy.INTERVAL_START; import org.apache.log4j.Logger; import org.apache.rya.indexing.StatementConstraints; import org.apache.rya.indexing.TemporalIndexer; import org.apache.rya.indexing.TemporalInstant; import org.apache.rya.indexing.TemporalInterval; import org.apache.rya.indexing.accumulo.ConfigUtils; import org.apache.rya.indexing.mongodb.AbstractMongoIndexer; import org.openrdf.model.Statement; import org.openrdf.query.QueryEvaluationException; import com.google.common.annotations.VisibleForTesting; import com.mongodb.DBCollection; import com.mongodb.QueryBuilder; import info.aduna.iteration.CloseableIteration; /** * Indexes MongoDB based on time instants or intervals. */ public class MongoTemporalIndexer extends AbstractMongoIndexer<TemporalMongoDBStorageStrategy> implements TemporalIndexer { private static final String COLLECTION_SUFFIX = "temporal"; private static final Logger LOG = Logger.getLogger(MongoTemporalIndexer.class); @Override public void init() { initCore(); predicates = ConfigUtils.getTemporalPredicates(conf); if (predicates.size() == 0) { LOG.debug( "No predicates specified for temporal indexing. During insertion, all statements will be attempted to be indexed into the temporal indexer."); } storageStrategy = new TemporalMongoDBStorageStrategy(); storageStrategy.createIndices(collection); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantEqualsInstant( final TemporalInstant queryInstant, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INSTANT).is(queryInstant.getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantBeforeInstant( final TemporalInstant queryInstant, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INSTANT).lessThan(queryInstant.getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantAfterInstant( final TemporalInstant queryInstant, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INSTANT).greaterThan(queryInstant.getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantBeforeInterval( final TemporalInterval givenInterval, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INSTANT) .lessThan(givenInterval.getHasBeginning().getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantAfterInterval( final TemporalInterval givenInterval, final StatementConstraints constraints) throws QueryEvaluationException { return queryInstantAfterInstant(givenInterval.getHasEnd(), constraints); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantInsideInterval( final TemporalInterval givenInterval, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INSTANT) .greaterThan(givenInterval.getHasBeginning().getAsDateTime().toDate()) .lessThan(givenInterval.getHasEnd().getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantHasBeginningInterval( final TemporalInterval queryInterval, final StatementConstraints constraints) throws QueryEvaluationException { return queryInstantEqualsInstant(queryInterval.getHasBeginning(), constraints); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryInstantHasEndInterval( final TemporalInterval queryInterval, final StatementConstraints constraints) throws QueryEvaluationException { return queryInstantEqualsInstant(queryInterval.getHasEnd(), constraints); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryIntervalEquals(final TemporalInterval query, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INTERVAL_START) .is(query.getHasBeginning().getAsDateTime().toDate()).and(INTERVAL_END) .is(query.getHasEnd().getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryIntervalBefore(final TemporalInterval query, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INTERVAL_END) .lessThan(query.getHasBeginning().getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public CloseableIteration<Statement, QueryEvaluationException> queryIntervalAfter(final TemporalInterval query, final StatementConstraints constraints) throws QueryEvaluationException { final QueryBuilder qb = QueryBuilder.start(INTERVAL_START) .greaterThan(query.getHasEnd().getAsDateTime().toDate()); return withConstraints(constraints, qb.get()); } @Override public String getCollectionName() { return ConfigUtils.getTablePrefix(conf) + COLLECTION_SUFFIX; } @VisibleForTesting public DBCollection getCollection() { return collection; } }