java版本kafka createStream

package com.ys.streaming;


import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;


import org.apache.spark.SparkConf;
import org.apache.spark.api.java.function.FlatMapFunction;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.streaming.Durations;
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 scala.Tuple2;


public class KafkaReceiver {
public static void main(String[] args) {

SparkConf conf = new SparkConf().setAppName("KafkaReceiver").setMaster("local[2]");
JavaStreamingContext jsc = new JavaStreamingContext(conf, Durations.seconds(5));


Map<String, Integer> topics = new HashMap<String, Integer>();
topics.put("20170420", 2);

/**
* 第一个参数是StreamingContext实例
* 第二个参数是ZooKeeper集群信息
* 第三个参数是Consumer Group
* 第四个参数是消费的Topic以及并发读取Topic中Partition的并发数
*/
JavaPairReceiverInputDStream<String, String> lines = KafkaUtils.createStream(
jsc, 
"master:2181,slave1:2181,slave2:2181", 
"myGroup", 
topics);

JavaDStream<String> words = lines.flatMap(new FlatMapFunction<Tuple2<String,String>, String>() {


private static final long serialVersionUID = 1L;


@Override
public Iterable<String> call(Tuple2<String, String> tuple) throws Exception {
return Arrays.asList(tuple._2.split(" "));
}
});

JavaPairDStream<String, Integer> pairs = words.mapToPair(new PairFunction<String, String, Integer>() {


private static final long serialVersionUID = 1L;


@Override
public Tuple2<String, Integer> call(String word) throws Exception {
return new Tuple2<String, Integer>(word, 1);
}
});

JavaPairDStream<String, Integer> result = pairs.reduceByKey(new Function2<Integer, Integer, Integer>() {

private static final long serialVersionUID = 1L;


@Override
public Integer call(Integer v1, Integer v2) throws Exception {
return v1 + v2;
}
});

result.print();

jsc.start();
jsc.awaitTermination();
jsc.close();
}
}