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.flume.source.twitter; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.text.DecimalFormat; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import org.apache.avro.Schema; import org.apache.avro.Schema.Field; import org.apache.avro.Schema.Type; import org.apache.avro.file.DataFileWriter; import org.apache.avro.generic.GenericData.Record; import org.apache.avro.generic.GenericDatumWriter; import org.apache.avro.generic.GenericRecord; import org.apache.avro.io.DatumWriter; import org.apache.flume.Context; import org.apache.flume.Event; import org.apache.flume.EventDrivenSource; import org.apache.flume.annotations.InterfaceAudience; import org.apache.flume.annotations.InterfaceStability; import org.apache.flume.conf.Configurable; import org.apache.flume.event.EventBuilder; import org.apache.flume.source.AbstractSource; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import twitter4j.MediaEntity; import twitter4j.StallWarning; import twitter4j.Status; import twitter4j.StatusDeletionNotice; import twitter4j.StatusListener; import twitter4j.TwitterStream; import twitter4j.TwitterStreamFactory; import twitter4j.User; import twitter4j.auth.AccessToken; /** * Demo Flume source that connects via Streaming API to the 1% sample twitter * firehose, continously downloads tweets, converts them to Avro format and * sends Avro events to a downstream Flume sink. * * Requires the consumer and access tokens and secrets of a Twitter developer * account */ @InterfaceAudience.Private @InterfaceStability.Unstable public class TwitterSource extends AbstractSource implements EventDrivenSource, Configurable, StatusListener { private TwitterStream twitterStream; private Schema avroSchema; private long docCount = 0; private long startTime = 0; private long exceptionCount = 0; private long totalTextIndexed = 0; private long skippedDocs = 0; private long batchEndTime = 0; private final List<Record> docs = new ArrayList<Record>(); private final ByteArrayOutputStream serializationBuffer = new ByteArrayOutputStream(); private DataFileWriter<GenericRecord> dataFileWriter; private int maxBatchSize = 1000; private int maxBatchDurationMillis = 1000; // Fri May 14 02:52:55 +0000 2010 private SimpleDateFormat formatterTo = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'"); private DecimalFormat numFormatter = new DecimalFormat("###,###.###"); private static int REPORT_INTERVAL = 100; private static int STATS_INTERVAL = REPORT_INTERVAL * 10; private static final Logger LOGGER = LoggerFactory.getLogger(TwitterSource.class); public TwitterSource() { } @Override public void configure(Context context) { String consumerKey = context.getString("consumerKey"); String consumerSecret = context.getString("consumerSecret"); String accessToken = context.getString("accessToken"); String accessTokenSecret = context.getString("accessTokenSecret"); LOGGER.info("Consumer Key: '" + consumerKey + "'"); LOGGER.info("Consumer Secret: '" + consumerSecret + "'"); LOGGER.info("Access Token: '" + accessToken + "'"); LOGGER.info("Access Token Secret: '" + accessTokenSecret + "'"); twitterStream = new TwitterStreamFactory().getInstance(); twitterStream.setOAuthConsumer(consumerKey, consumerSecret); twitterStream.setOAuthAccessToken(new AccessToken(accessToken, accessTokenSecret)); twitterStream.addListener(this); avroSchema = createAvroSchema(); dataFileWriter = new DataFileWriter<GenericRecord>(new GenericDatumWriter<GenericRecord>(avroSchema)); maxBatchSize = context.getInteger("maxBatchSize", maxBatchSize); maxBatchDurationMillis = context.getInteger("maxBatchDurationMillis", maxBatchDurationMillis); } @Override public synchronized void start() { LOGGER.info("Starting twitter source {} ...", this); docCount = 0; startTime = System.currentTimeMillis(); exceptionCount = 0; totalTextIndexed = 0; skippedDocs = 0; batchEndTime = System.currentTimeMillis() + maxBatchDurationMillis; twitterStream.sample(); LOGGER.info("Twitter source {} started.", getName()); // This should happen at the end of the start method, since this will // change the lifecycle status of the component to tell the Flume // framework that this component has started. Doing this any earlier // tells the framework that the component started successfully, even // if the method actually fails later. super.start(); } @Override public synchronized void stop() { LOGGER.info("Twitter source {} stopping...", getName()); twitterStream.shutdown(); super.stop(); LOGGER.info("Twitter source {} stopped.", getName()); } public void onStatus(Status status) { Record doc = extractRecord("", avroSchema, status); if (doc == null) { return; // skip } docs.add(doc); if (docs.size() >= maxBatchSize || System.currentTimeMillis() >= batchEndTime) { batchEndTime = System.currentTimeMillis() + maxBatchDurationMillis; byte[] bytes; try { bytes = serializeToAvro(avroSchema, docs); } catch (IOException e) { LOGGER.error("Exception while serializing tweet", e); return; //skip } Event event = EventBuilder.withBody(bytes); getChannelProcessor().processEvent(event); // send event to the flume sink docs.clear(); } docCount++; if ((docCount % REPORT_INTERVAL) == 0) { LOGGER.info(String.format("Processed %s docs", numFormatter.format(docCount))); } if ((docCount % STATS_INTERVAL) == 0) { logStats(); } } private Schema createAvroSchema() { Schema avroSchema = Schema.createRecord("Doc", "adoc", null, false); List<Field> fields = new ArrayList<Field>(); fields.add(new Field("id", Schema.create(Type.STRING), null, null)); fields.add(new Field("user_friends_count", createOptional(Schema.create(Type.INT)), null, null)); fields.add(new Field("user_location", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("user_description", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("user_statuses_count", createOptional(Schema.create(Type.INT)), null, null)); fields.add(new Field("user_followers_count", createOptional(Schema.create(Type.INT)), null, null)); fields.add(new Field("user_name", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("user_screen_name", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("created_at", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("text", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("retweet_count", createOptional(Schema.create(Type.LONG)), null, null)); fields.add(new Field("retweeted", createOptional(Schema.create(Type.BOOLEAN)), null, null)); fields.add(new Field("in_reply_to_user_id", createOptional(Schema.create(Type.LONG)), null, null)); fields.add(new Field("source", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("in_reply_to_status_id", createOptional(Schema.create(Type.LONG)), null, null)); fields.add(new Field("media_url_https", createOptional(Schema.create(Type.STRING)), null, null)); fields.add(new Field("expanded_url", createOptional(Schema.create(Type.STRING)), null, null)); avroSchema.setFields(fields); return avroSchema; } private Record extractRecord(String idPrefix, Schema avroSchema, Status status) { User user = status.getUser(); Record doc = new Record(avroSchema); doc.put("id", idPrefix + status.getId()); doc.put("created_at", formatterTo.format(status.getCreatedAt())); doc.put("retweet_count", status.getRetweetCount()); doc.put("retweeted", status.isRetweet()); doc.put("in_reply_to_user_id", status.getInReplyToUserId()); doc.put("in_reply_to_status_id", status.getInReplyToStatusId()); addString(doc, "source", status.getSource()); addString(doc, "text", status.getText()); MediaEntity[] mediaEntities = status.getMediaEntities(); if (mediaEntities.length > 0) { addString(doc, "media_url_https", mediaEntities[0].getMediaURLHttps()); addString(doc, "expanded_url", mediaEntities[0].getExpandedURL()); } doc.put("user_friends_count", user.getFriendsCount()); doc.put("user_statuses_count", user.getStatusesCount()); doc.put("user_followers_count", user.getFollowersCount()); addString(doc, "user_location", user.getLocation()); addString(doc, "user_description", user.getDescription()); addString(doc, "user_screen_name", user.getScreenName()); addString(doc, "user_name", user.getName()); return doc; } private byte[] serializeToAvro(Schema avroSchema, List<Record> docList) throws IOException { serializationBuffer.reset(); dataFileWriter.create(avroSchema, serializationBuffer); for (Record doc2 : docList) { dataFileWriter.append(doc2); } dataFileWriter.close(); return serializationBuffer.toByteArray(); } private Schema createOptional(Schema schema) { return Schema.createUnion(Arrays.asList(new Schema[] { schema, Schema.create(Type.NULL) })); } private void addString(Record doc, String avroField, String val) { if (val == null) { return; } doc.put(avroField, val); totalTextIndexed += val.length(); } private void logStats() { double mbIndexed = totalTextIndexed / (1024 * 1024.0); long seconds = (System.currentTimeMillis() - startTime) / 1000; seconds = Math.max(seconds, 1); LOGGER.info(String.format("Total docs indexed: %s, total skipped docs: %s", numFormatter.format(docCount), numFormatter.format(skippedDocs))); LOGGER.info(String.format(" %s docs/second", numFormatter.format(docCount / seconds))); LOGGER.info(String.format("Run took %s seconds and processed:", numFormatter.format(seconds))); LOGGER.info(String.format(" %s MB/sec sent to index", numFormatter.format(((float) totalTextIndexed / (1024 * 1024)) / seconds))); LOGGER.info(String.format(" %s MB text sent to index", numFormatter.format(mbIndexed))); LOGGER.info(String.format("There were %s exceptions ignored: ", numFormatter.format(exceptionCount))); } public void onDeletionNotice(StatusDeletionNotice statusDeletionNotice) { // Do nothing... } public void onScrubGeo(long userId, long upToStatusId) { // Do nothing... } public void onStallWarning(StallWarning warning) { // Do nothing... } public void onTrackLimitationNotice(int numberOfLimitedStatuses) { // Do nothing... } public void onException(Exception e) { LOGGER.error("Exception while streaming tweets", e); } }