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.pulsar.io.mongodb; import com.google.common.collect.Lists; import com.mongodb.MongoBulkWriteException; import com.mongodb.async.client.MongoClient; import com.mongodb.async.client.MongoClients; import com.mongodb.async.client.MongoCollection; import com.mongodb.async.client.MongoDatabase; import lombok.extern.slf4j.Slf4j; import org.apache.pulsar.functions.api.Record; import org.apache.pulsar.io.core.Sink; import org.apache.pulsar.io.core.SinkContext; import org.apache.pulsar.io.core.annotations.Connector; import org.apache.pulsar.io.core.annotations.IOType; import org.bson.BSONException; import org.bson.Document; import org.bson.json.JsonParseException; import java.nio.charset.Charset; import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.TimeUnit; import java.util.stream.IntStream; import static java.util.stream.Collectors.toList; /** * The base class for MongoDB sinks. * Users need to implement extractKeyValue function to use this sink. * This class assumes that the input will be JSON documents. */ @Connector(name = "mongo", type = IOType.SINK, help = "A sink connector that sends pulsar messages to mongodb", configClass = MongoConfig.class) @Slf4j public class MongoSink implements Sink<byte[]> { private MongoConfig mongoConfig; private MongoClient mongoClient; private MongoCollection<Document> collection; private List<Record<byte[]>> incomingList; private ScheduledExecutorService flushExecutor; @Override public void open(Map<String, Object> config, SinkContext sinkContext) throws Exception { log.info("Open MongoDB Sink"); mongoConfig = MongoConfig.load(config); mongoConfig.validate(); mongoClient = MongoClients.create(mongoConfig.getMongoUri()); final MongoDatabase db = mongoClient.getDatabase(mongoConfig.getDatabase()); collection = db.getCollection(mongoConfig.getCollection()); incomingList = Lists.newArrayList(); flushExecutor = Executors.newScheduledThreadPool(1); flushExecutor.scheduleAtFixedRate(() -> flush(), mongoConfig.getBatchTimeMs(), mongoConfig.getBatchTimeMs(), TimeUnit.MILLISECONDS); } @Override public void write(Record<byte[]> record) { final String recordValue = new String(record.getValue(), Charset.forName("UTF-8")); if (log.isDebugEnabled()) { log.debug("Received record: " + recordValue); } int currentSize; synchronized (this) { incomingList.add(record); currentSize = incomingList.size(); } if (currentSize == mongoConfig.getBatchSize()) { flushExecutor.submit(() -> flush()); } } private void flush() { final List<Document> docsToInsert = new ArrayList<>(); final List<Record<byte[]>> recordsToInsert; synchronized (this) { if (incomingList.isEmpty()) { return; } recordsToInsert = incomingList; incomingList = Lists.newArrayList(); } final Iterator<Record<byte[]>> iter = recordsToInsert.iterator(); while (iter.hasNext()) { final Record<byte[]> record = iter.next(); try { final byte[] docAsBytes = record.getValue(); final Document doc = Document.parse(new String(docAsBytes, Charset.forName("UTF-8"))); docsToInsert.add(doc); } catch (JsonParseException | BSONException e) { log.error("Bad message", e); record.fail(); iter.remove(); } } if (docsToInsert.size() > 0) { collection.insertMany(docsToInsert, (result, t) -> { final List<Integer> idxToAck = IntStream.range(0, docsToInsert.size()).boxed().collect(toList()); final List<Integer> idxToFail = Lists.newArrayList(); if (t != null) { log.error("MongoDB insertion error", t); if (t instanceof MongoBulkWriteException) { // With this exception, we are aware of the items that have not been inserted. ((MongoBulkWriteException) t).getWriteErrors().forEach(err -> { idxToFail.add(err.getIndex()); }); idxToAck.removeAll(idxToFail); } else { idxToFail.addAll(idxToAck); idxToAck.clear(); } } if (log.isDebugEnabled()) { log.debug("Nb ack={}, nb fail={}", idxToAck.size(), idxToFail.size()); } idxToAck.forEach(idx -> recordsToInsert.get(idx).ack()); idxToFail.forEach(idx -> recordsToInsert.get(idx).fail()); }); } } @Override public void close() throws Exception { if (flushExecutor != null) { flushExecutor.shutdown(); } if (mongoClient != null) { mongoClient.close(); } } }