Java Queue Stream in apache spark - Java Big Data

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Description

Java Queue Stream in apache spark

Demo Code

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 * this work for additional information regarding copyright ownership.
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 * (the "License"); you may not use this file except in compliance with
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package eduonix.spark.streaming;

import java.util.LinkedList;
import java.util.List;
import java.util.Queue;

import scala.Tuple2;

import com.google.common.collect.Lists;

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.function.Function2;
import org.apache.spark.api.java.function.PairFunction;
import org.apache.spark.examples.streaming.StreamingExamples;
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;

public final class JavaQueueStream {
    private JavaQueueStream() {
    }

    public static void main(String[] args) throws Exception {

        StreamingExamples.setStreamingLogLevels();
        SparkConf sparkConf = new SparkConf().setAppName("JavaQueueStream");

        // Create the context
        JavaStreamingContext ssc = new JavaStreamingContext(sparkConf,
                new Duration(1000));

        // Create the queue through which RDDs can be pushed to
        // a QueueInputDStream
        Queue<JavaRDD<Integer>> rddQueue = new LinkedList<JavaRDD<Integer>>();

        // Create and push some RDDs into the queue
        List<Integer> list = Lists.newArrayList();
        for (int i = 0; i < 1000; i++) {
            list.add(i);
        }

        for (int i = 0; i < 30; i++) {
            rddQueue.add(ssc.sparkContext().parallelize(list));
        }

        // Create the QueueInputDStream and use it do some processing
        JavaDStream<Integer> inputStream = ssc.queueStream(rddQueue);
        JavaPairDStream<Integer, Integer> mappedStream = inputStream
                .mapToPair(new PairFunction<Integer, Integer, Integer>() {
                    @Override
                    public Tuple2<Integer, Integer> call(Integer i) {
                        return new Tuple2<Integer, Integer>(i % 10, 1);
                    }
                });
        JavaPairDStream<Integer, Integer> reducedStream = mappedStream
                .reduceByKey(new Function2<Integer, Integer, Integer>() {
                    @Override
                    public Integer call(Integer i1, Integer i2) {
                        return i1 + i2;
                    }
                });

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

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