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 com.kakfa.spark; import java.util.Map; import java.util.HashMap; import java.util.regex.Pattern; import scala.Tuple2; import org.apache.log4j.Logger; import org.apache.log4j.Level; import com.google.common.collect.Lists; import org.apache.spark.SparkConf; import org.apache.spark.api.java.function.FlatMapFunction; import org.apache.spark.api.java.function.Function; import org.apache.spark.api.java.function.Function2; import org.apache.spark.api.java.function.PairFunction; import org.apache.spark.examples.streaming.StreamingExamples; import kafka.serializer.Decoder; import kafka.serializer.Encoder; import org.apache.spark.streaming.Duration; import org.apache.spark.streaming.api.java.JavaDStream; import org.apache.spark.streaming.api.java.JavaPairDStream; import org.apache.spark.streaming.api.java.JavaPairReceiverInputDStream; import org.apache.spark.streaming.api.java.JavaStreamingContext; import org.apache.spark.streaming.kafka.KafkaUtils; import org.apache.spark.streaming.kafka.*; /** * Consumes messages from one or more topics in Kafka and does wordcount. * * Usage: JavaKafkaWordCount <zkQuorum> <group> <topics> <numThreads> * <zkQuorum> is a list of one or more zookeeper servers that make quorum * <group> is the name of kafka consumer group * <topics> is a list of one or more kafka topics to consume from * <numThreads> is the number of threads the kafka consumer should use * * To run this example: * `$ bin/run-example org.apache.spark.examples.streaming.JavaKafkaWordCount zoo01,zoo02, \ * zoo03 my-consumer-group topic1,topic2 1` */ public final class JavaKafkaWordCount { // private static final Pattern SPACE = Pattern.compile(" "); protected static final Pattern SPACE = Pattern.compile(" "); private JavaKafkaWordCount() { } public static void main(String[] args) { if (args.length < 4) { System.err.println("Usage: JavaKafkaWordCount <zkQuorum> <group> <topics> <numThreads>"); System.exit(1); } StreamingExamples.setStreamingLogLevels(); //SparkConf sparkConf = new SparkConf().setAppName("JavaKafkaWordCount"); //sparkConf.setMaster("spark://60f81dc6426c:7077"); // SparkConf sparkConf = new SparkConf().setAppName("JavaKafkaWordCount").setMaster("spark://60f81dc6426c:7077"); // Create the context with a 1 second batch size JavaStreamingContext jssc = new JavaStreamingContext("local[4]", "JavaKafkaWordCount", new Duration(2000)); int numThreads = Integer.parseInt(args[3]); Logger.getLogger("org").setLevel(Level.OFF); Logger.getLogger("akka").setLevel(Level.OFF); Map<String, Integer> topicMap = new HashMap<String, Integer>(); String[] topics = args[2].split(","); for (String topic : topics) { topicMap.put(topic, numThreads); } /* for(String t: topic) { topicMap.put(t, new Integer(3)); }*/ // NotSerializable notSerializable = new NotSerializable(); //JavaRDD<String> rdd = sc.textFile("/tmp/myfile"); // rdd.map(s -> notSerializable.doSomething(s)).collect(); JavaPairReceiverInputDStream<String, String> messages = KafkaUtils.createStream(jssc, args[0], args[1], topicMap); //JavaPairReceiverInputDStream<String, String> kafkaStream = // KafkaUtils.createStream(jssc, "localhost:2181","streamingContext", // topicMap); System.out.println("Connection !!!!"); /*JavaDStream<String> data = messages.map(new Function<Tuple2<String, String>, String>() { public String call(Tuple2<String, String> message) { return message._2(); } } );*/ JavaDStream<String> lines = messages.map(new Function<Tuple2<String, String>, String>() { @Override public String call(Tuple2<String, String> tuple2) { return tuple2._2(); } }); JavaDStream<String> words = lines.flatMap(new FlatMapFunction<String, String>() { @Override public Iterable<String> call(String x) { return Lists.newArrayList(SPACE.split(x)); } }); JavaPairDStream<String, Integer> wordCounts = words.mapToPair(new PairFunction<String, String, Integer>() { @Override public Tuple2<String, Integer> call(String s) { return new Tuple2<String, Integer>(s, 1); } }).reduceByKey(new Function2<Integer, Integer, Integer>() { @Override public Integer call(Integer i1, Integer i2) { return i1 + i2; } }); wordCounts.print(); jssc.start(); jssc.awaitTermination(); } }