Java tutorial
/* * Copyright 2016 Crown Copyright * * Licensed 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. */ package gaffer.accumulostore.operation.spark.handler; import gaffer.accumulostore.AccumuloStore; import gaffer.accumulostore.key.exception.IteratorSettingException; import gaffer.accumulostore.key.exception.RangeFactoryException; import gaffer.commonutil.CommonConstants; import gaffer.data.element.Element; import gaffer.operation.GetOperation; import gaffer.operation.OperationException; import gaffer.operation.data.ElementSeed; import gaffer.store.StoreException; import gaffer.store.operation.handler.OperationHandler; import org.apache.accumulo.core.client.IteratorSetting; import org.apache.accumulo.core.client.mapreduce.AccumuloInputFormat; import org.apache.accumulo.core.client.mapreduce.lib.impl.InputConfigurator; import org.apache.accumulo.core.data.Range; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.io.NullWritable; import scala.Tuple2; import scala.runtime.AbstractFunction1; import java.io.ByteArrayInputStream; import java.io.DataInputStream; import java.io.IOException; import java.io.Serializable; import java.util.ArrayList; import java.util.List; public abstract class AbstractGetRDDOperationHandler<OUTPUT, OP_TYPE extends GetOperation<?, OUTPUT>> implements OperationHandler<OP_TYPE, OUTPUT> { public static final String HADOOP_CONFIGURATION_KEY = "Hadoop_Configuration_Key"; void addIterators(final AccumuloStore accumuloStore, final Configuration conf, final GetOperation<?, ?> operation) throws OperationException { try { // Update configuration with instance name, table name, zookeepers, and with view accumuloStore.updateConfiguration(conf, operation.getView()); // Add iterators based on operation-specific (i.e. not view related) options final IteratorSetting edgeEntityDirectionFilter = accumuloStore.getKeyPackage().getIteratorFactory() .getEdgeEntityDirectionFilterIteratorSetting(operation); if (edgeEntityDirectionFilter != null) { InputConfigurator.addIterator(AccumuloInputFormat.class, conf, edgeEntityDirectionFilter); } final IteratorSetting queryTimeAggregator = accumuloStore.getKeyPackage().getIteratorFactory() .getQueryTimeAggregatorIteratorSetting(operation.getView(), accumuloStore); if (queryTimeAggregator != null) { InputConfigurator.addIterator(AccumuloInputFormat.class, conf, queryTimeAggregator); } } catch (final StoreException | IteratorSettingException e) { throw new OperationException("Failed to update configuration", e); } } <ELEMENT_SEED extends ElementSeed> void addRanges(final AccumuloStore accumuloStore, final Configuration conf, final GetOperation<ELEMENT_SEED, ?> operation) throws OperationException { final List<Range> ranges = new ArrayList<>(); for (final ELEMENT_SEED entitySeed : operation.getSeeds()) { try { ranges.addAll(accumuloStore.getKeyPackage().getRangeFactory().getRange(entitySeed, operation)); } catch (final RangeFactoryException e) { throw new OperationException("Failed to add ranges to configuration", e); } } InputConfigurator.setRanges(AccumuloInputFormat.class, conf, ranges); } protected Configuration getConfiguration(final GetOperation<?, ?> operation) throws OperationException { final Configuration conf = new Configuration(); final String serialisedConf = operation.getOption(AbstractGetRDDOperationHandler.HADOOP_CONFIGURATION_KEY); if (serialisedConf != null) { try { final ByteArrayInputStream bais = new ByteArrayInputStream( serialisedConf.getBytes(CommonConstants.UTF_8)); conf.readFields(new DataInputStream(bais)); } catch (final IOException e) { throw new OperationException("Exception decoding Configuration from options", e); } } return conf; } static class FirstElement extends AbstractFunction1<Tuple2<Element, NullWritable>, Element> implements Serializable { private static final long serialVersionUID = -5693778654823431294L; @Override public Element apply(final Tuple2<Element, NullWritable> tuple) { return tuple._1(); } } }