StreamingApp1.java

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.Duration;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;
import org.apache.spark.streaming.scheduler.*;
import scala.Tuple2;

import java.util.Arrays;

public class StreamingApp1 {

    public static void main(String[] args) {
        SparkConf sparkConf = new SparkConf().setAppName("JavaWordCount");
        Duration batchInterval = new Duration(2000);
        final JavaStreamingContext ssc = new JavaStreamingContext(sparkConf, batchInterval);
        JavaDStream<String> lines = ssc.textFileStream("...");

        JavaDStream<String> words = lines.flatMap(new FlatMapFunction<String, String>() {
            @Override
            public Iterable<String> call(String s) {
                return Arrays.asList(s.split(" "));
            }
        });

        JavaPairDStream<String, Integer> ones = words.mapToPair(new PairFunction<String, String, Integer>() {
            @Override
            public Tuple2<String, Integer> call(String s) {
                return new Tuple2<String, Integer>(s, 1);
            }
        });

        JavaPairDStream<String, Integer> counts = ones.reduceByKey(new Function2<Integer, Integer, Integer>() {
            @Override
            public Integer call(Integer i1, Integer i2) {
                return i1 + i2;
            }
        });
        counts.print();

        ssc.addStreamingListener(new StreamingListener() {

            private int completedBatchCount = 0;

            @Override
            public void onReceiverStarted(StreamingListenerReceiverStarted receiverStarted) {
            }

            @Override
            public void onReceiverError(StreamingListenerReceiverError receiverError) {
            }

            @Override
            public void onReceiverStopped(StreamingListenerReceiverStopped receiverStopped) {
            }

            @Override
            public void onBatchSubmitted(StreamingListenerBatchSubmitted batchSubmitted) {
            }

            @Override
            public void onBatchStarted(StreamingListenerBatchStarted batchStarted) {
            }

            @Override
            public void onBatchCompleted(StreamingListenerBatchCompleted batchCompleted) {
                completedBatchCount += 1;
                if (completedBatchCount == 10) {
                    // Note: because this runs asynchronously, it's possible that we launch more than 10 batches
                    System.out.println(completedBatchCount + " batches has completed");
                    new Thread() {
                        @Override
                        public void run() {
                            ssc.stop(true, true);
                        }
                    }.start();
                }
            }

        });
        ssc.start();
        ssc.awaitTermination();
    }
}