SparkStreaming小例子

1.安裝nc纔可以打開端口
rpm -ivh /media/CentOS_6.7_Final/Packages/nmap-5.51-4.el6.x86_64.rpm
2.ncat -lk 1234
3.
package com.iflytek.sparkstreaming;

import java.util.Arrays;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaSparkContext;
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.Durations;
import org.apache.spark.streaming.api.java.JavaDStream;
import org.apache.spark.streaming.api.java.JavaPairDStream;
import org.apache.spark.streaming.api.java.JavaReceiverInputDStream;
import org.apache.spark.streaming.api.java.JavaStreamingContext;

import scala.Tuple2;
import scala.collection.generic.BitOperations.Int;
import scala.collection.script.Start;
import sun.net.www.content.audio.x_aiff;

public class SparkStreaming {

 public static void main(String[] args) {
  SparkConf sparkConf = new SparkConf().setAppName("sparkSQL");
  sparkConf.setMaster("local[2]");
  System.setProperty("hadoop.home.dir", "E:\\spark\\spark-1.6.1-bin-hadoop2.6");
//  JavaSparkContext sc = new JavaSparkContext(sparkConf);
  
  JavaStreamingContext jssc=new JavaStreamingContext(sparkConf,Durations.seconds(3));
  Logger.getRootLogger().setLevel(Level.OFF);
  JavaReceiverInputDStream<String> lines=jssc.socketTextStream("h1", 1234);
  JavaDStream<String> words=lines.flatMap(new FlatMapFunction<String,String>() {

   public Iterable<String> call(String x) throws Exception {
    return Arrays.asList(x.split(" "));
   }
  });
  JavaPairDStream<String, Integer> pairs=words.mapToPair(new PairFunction<String, String, Integer>() {

   public Tuple2<String, Integer> call(String s) throws Exception {
    return new Tuple2<>(s,1);
   }
  });
  JavaPairDStream<String, Integer> javaPairDStream=pairs.reduceByKey(new Function2<Integer, Integer, Integer>() {
   
   @Override
   public Integer call(Integer arg0, Integer arg1) throws Exception {
    return arg0+arg1;
   }
  });
  javaPairDStream.print();
  jssc.start();
  jssc.awaitTermination();
  

 }

}

4.截圖

注意：如果向端口發送的信息在控制檯顯示不出來，記得修改端口號，有可能這個端口被佔用。