Adding files for the tutorial BAEL-2301 (#6066)

This commit is contained in:
Kumar Chandrakant
2019-01-05 17:52:23 +05:30
committed by Grzegorz Piwowarek
parent a3d6ebef5c
commit b1352b58e0
4 changed files with 345 additions and 4 deletions

View File

@@ -0,0 +1,25 @@
package com.baeldung.data.pipeline;
import java.io.Serializable;
public class Word implements Serializable {
private static final long serialVersionUID = 1L;
private String word;
private int count;
Word(String word, int count) {
this.word = word;
this.count = count;
}
public String getWord() {
return word;
}
public void setWord(String word) {
this.word = word;
}
public int getCount() {
return count;
}
public void setCount(int count) {
this.count = count;
}
}

View File

@@ -0,0 +1,116 @@
package com.baeldung.data.pipeline;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.javaFunctions;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.mapToRow;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
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.api.java.function.VoidFunction;
import org.apache.spark.streaming.Durations;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaInputDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;
import org.apache.spark.streaming.kafka010.ConsumerStrategies;
import org.apache.spark.streaming.kafka010.KafkaUtils;
import org.apache.spark.streaming.kafka010.LocationStrategies;
import scala.Tuple2;
public class WordCountingApp {
@SuppressWarnings("serial")
public static void main(String[] args) throws InterruptedException {
Logger.getLogger("org")
.setLevel(Level.OFF);
Logger.getLogger("akka")
.setLevel(Level.OFF);
Map<String, Object> kafkaParams = new HashMap<>();
kafkaParams.put("bootstrap.servers", "localhost:9092");
kafkaParams.put("key.deserializer", StringDeserializer.class);
kafkaParams.put("value.deserializer", StringDeserializer.class);
kafkaParams.put("group.id", "use_a_separate_group_id_for_each_stream");
kafkaParams.put("auto.offset.reset", "latest");
kafkaParams.put("enable.auto.commit", false);
Collection<String> topics = Arrays.asList("messages");
SparkConf sparkConf = new SparkConf();
sparkConf.setMaster("local[2]");
sparkConf.setAppName("WordCountingApp");
sparkConf.set("spark.cassandra.connection.host", "127.0.0.1");
JavaStreamingContext streamingContext = new JavaStreamingContext(sparkConf, Durations.seconds(1));
JavaInputDStream<ConsumerRecord<String, String>> messages = KafkaUtils.createDirectStream(streamingContext, LocationStrategies.PreferConsistent(), ConsumerStrategies.<String, String> Subscribe(topics, kafkaParams));
JavaPairDStream<String, String> results = messages.mapToPair(new PairFunction<ConsumerRecord<String, String>, String, String>() {
@Override
public Tuple2<String, String> call(ConsumerRecord<String, String> record) {
return new Tuple2<>(record.key(), record.value());
}
});
JavaDStream<String> lines = results.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 Iterator<String> call(String x) {
return Arrays.asList(x.split("\\s+"))
.iterator();
}
});
JavaPairDStream<String, Integer> wordCounts = words.mapToPair(new PairFunction<String, String, Integer>() {
@Override
public Tuple2<String, Integer> call(String s) {
return new Tuple2<>(s, 1);
}
})
.reduceByKey(new Function2<Integer, Integer, Integer>() {
@Override
public Integer call(Integer i1, Integer i2) {
return i1 + i2;
}
});
wordCounts.foreachRDD(new VoidFunction<JavaPairRDD<String, Integer>>() {
@Override
public void call(JavaPairRDD<String, Integer> javaRdd) throws Exception {
Map<String, Integer> wordCountMap = javaRdd.collectAsMap();
for (String key : wordCountMap.keySet()) {
List<Word> words = Arrays.asList(new Word(key, wordCountMap.get(key)));
JavaRDD<Word> rdd = streamingContext.sparkContext()
.parallelize(words);
javaFunctions(rdd).writerBuilder("vocabulary", "words", mapToRow(Word.class))
.saveToCassandra();
}
}
});
streamingContext.start();
streamingContext.awaitTermination();
}
}

View File

@@ -0,0 +1,140 @@
package com.baeldung.data.pipeline;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.javaFunctions;
import static com.datastax.spark.connector.japi.CassandraJavaUtil.mapToRow;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.kafka.clients.consumer.ConsumerRecord;
import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaPairRDD;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.Optional;
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.Function3;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.api.java.function.VoidFunction;
import org.apache.spark.streaming.Durations;
import org.apache.spark.streaming.State;
import org.apache.spark.streaming.StateSpec;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaInputDStream;
import org.apache.spark.streaming.api.java.JavaMapWithStateDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;
import org.apache.spark.streaming.kafka010.ConsumerStrategies;
import org.apache.spark.streaming.kafka010.KafkaUtils;
import org.apache.spark.streaming.kafka010.LocationStrategies;
import scala.Tuple2;
public class WordCountingAppWithCheckpoint {
public static JavaSparkContext sparkContext;
@SuppressWarnings("serial")
public static void main(String[] args) throws InterruptedException {
Logger.getLogger("org")
.setLevel(Level.OFF);
Logger.getLogger("akka")
.setLevel(Level.OFF);
Map<String, Object> kafkaParams = new HashMap<>();
kafkaParams.put("bootstrap.servers", "localhost:9092");
kafkaParams.put("key.deserializer", StringDeserializer.class);
kafkaParams.put("value.deserializer", StringDeserializer.class);
kafkaParams.put("group.id", "use_a_separate_group_id_for_each_stream");
kafkaParams.put("auto.offset.reset", "latest");
kafkaParams.put("enable.auto.commit", false);
Collection<String> topics = Arrays.asList("messages");
SparkConf sparkConf = new SparkConf();
sparkConf.setMaster("local[2]");
sparkConf.setAppName("WordCountingAppWithCheckpoint");
sparkConf.set("spark.cassandra.connection.host", "127.0.0.1");
JavaStreamingContext streamingContext = new JavaStreamingContext(sparkConf, Durations.seconds(1));
sparkContext = streamingContext.sparkContext();
streamingContext.checkpoint("./.checkpoint");
JavaInputDStream<ConsumerRecord<String, String>> messages = KafkaUtils.createDirectStream(streamingContext, LocationStrategies.PreferConsistent(), ConsumerStrategies.<String, String> Subscribe(topics, kafkaParams));
JavaPairDStream<String, String> results = messages.mapToPair(new PairFunction<ConsumerRecord<String, String>, String, String>() {
@Override
public Tuple2<String, String> call(ConsumerRecord<String, String> record) {
return new Tuple2<>(record.key(), record.value());
}
});
JavaDStream<String> lines = results.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 Iterator<String> call(String x) {
return Arrays.asList(x.split("\\s+"))
.iterator();
}
});
JavaPairDStream<String, Integer> wordCounts = words.mapToPair(new PairFunction<String, String, Integer>() {
@Override
public Tuple2<String, Integer> call(String s) {
return new Tuple2<>(s, 1);
}
})
.reduceByKey(new Function2<Integer, Integer, Integer>() {
@Override
public Integer call(Integer i1, Integer i2) {
return i1 + i2;
}
});
Function3<String, Optional<Integer>, State<Integer>, Tuple2<String, Integer>> mappingFunc = (word, one, state) -> {
int sum = one.orElse(0) + (state.exists() ? state.get() : 0);
Tuple2<String, Integer> output = new Tuple2<>(word, sum);
state.update(sum);
return output;
};
JavaPairRDD<String, Integer> initialRDD = JavaPairRDD.fromJavaRDD(sparkContext.emptyRDD());
JavaMapWithStateDStream<String, Integer, Integer, Tuple2<String, Integer>> cumulativeWordCounts = wordCounts.mapWithState(StateSpec.function(mappingFunc)
.initialState(initialRDD));
cumulativeWordCounts.foreachRDD(new VoidFunction<JavaRDD<Tuple2<String, Integer>>>() {
@Override
public void call(JavaRDD<Tuple2<String, Integer>> javaRdd) throws Exception {
List<Tuple2<String, Integer>> wordCountList = javaRdd.collect();
for (Tuple2<String, Integer> tuple : wordCountList) {
List<Word> words = Arrays.asList(new Word(tuple._1, tuple._2));
JavaRDD<Word> rdd = sparkContext.parallelize(words);
javaFunctions(rdd).writerBuilder("vocabulary", "words", mapToRow(Word.class))
.saveToCassandra();
}
}
});
streamingContext.start();
streamingContext.awaitTermination();
}
}