Java tutorial
/** * 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. */ package org.apache.metron.writer; import org.apache.storm.tuple.Tuple; import com.google.common.collect.Iterables; import org.apache.metron.common.configuration.writer.SingleBatchConfigurationFacade; import org.apache.metron.common.configuration.writer.WriterConfiguration; import org.apache.metron.common.writer.BulkMessageWriter; import org.apache.metron.common.writer.MessageWriter; import org.apache.metron.common.writer.BulkWriterResponse; import java.io.Serializable; import java.util.List; import java.util.Map; import java.util.function.Function; public class WriterToBulkWriter<MESSAGE_T> implements BulkMessageWriter<MESSAGE_T>, Serializable { MessageWriter<MESSAGE_T> messageWriter; public static transient Function<WriterConfiguration, WriterConfiguration> TRANSFORMATION = config -> new SingleBatchConfigurationFacade( config); public WriterToBulkWriter(MessageWriter<MESSAGE_T> messageWriter) { this.messageWriter = messageWriter; } @Override public void init(Map stormConf, WriterConfiguration config) throws Exception { messageWriter.init(); } @Override public BulkWriterResponse write(String sensorType, WriterConfiguration configurations, Iterable<Tuple> tuples, List<MESSAGE_T> messages) throws Exception { BulkWriterResponse response = new BulkWriterResponse(); if (messages.size() > 1) { response.addAllErrors(new IllegalStateException("WriterToBulkWriter expects a batch of exactly 1"), tuples); return response; } try { messageWriter.write(sensorType, configurations, Iterables.getFirst(tuples, null), Iterables.getFirst(messages, null)); } catch (Exception e) { response.addAllErrors(e, tuples); return response; } response.addAllSuccesses(tuples); return response; } @Override public String getName() { return messageWriter.getName(); } @Override public void close() throws Exception { messageWriter.close(); } }