spark读取redis数据（交互式，scala单机版，java单机版）

• 交互式

第一步：向redis中添加数据

第二步：将jedis jar包放入~/lib目录下，开启spark服务

第三步：通过spark-shell读取redis数据，并做相应处理

• scala单机版

package com.test

import org.apache.spark.SparkConf
import org.apache.spark.SparkContext

import redis.clients.jedis.Jedis

object RedisClient {
  def main(args: Array[String]) {

    val conf = new SparkConf()
    conf.setAppName("wow,my first spark app")
    conf.setMaster("local")
    val sc = new SparkContext(conf)
    var jd = new Jedis("172.171.51.154", 6379)
    var str = jd.get("chengshi")
    var strList = str.split(",")
    val a = sc.parallelize(strList, 3)
    val b = a.keyBy(_.length)
    b.collect().foreach(s => println(s._1 + ":" + s._2))

    sc.stop()
  }

}

输出结果

• java单机版

package com.dt.spark.SparkApps.cores;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Arrays;

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.function.PairFunction;
import org.apache.spark.api.java.function.VoidFunction;

import redis.clients.jedis.Jedis;
import scala.Tuple2;

public class Redis {

    public static void main(String[] args) throws FileNotFoundException, IOException {

        SparkConf conf = new SparkConf().setAppName("Spark Read From Redis written by Java").setMaster("local");
        JavaSparkContext sc = new JavaSparkContext(conf);
        Jedis jedis = new Jedis("172.171.51.154", 6379);

        String s = jedis.get("chengshi");
        String[] strList = s.split(",");

        JavaRDD ch = sc.parallelize(Arrays.asList(strList), 4);

        JavaPairRDD jp = ch.mapToPair(new PairFunction() {

            public Tuple2 call(String word) throws Exception {
                return new Tuple2(word, word.length());
            }
        });
        jp.foreach(new VoidFunction>() {

            public void call(Tuple2 pairs) throws Exception {
                System.out.println(pairs._1() + ":" + pairs._2());
            }
        });
        sc.close();

    }
}

输出结果