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

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第二步：将jedis jar包放入~/lib目录下，开启spark服务

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第三步：通过spark-shell读取redis数据，并做相应处理

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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<String> ch = sc .parallelize(Arrays .asList(strList),  4) ;

        JavaPairRDD<String, Integer> jp = ch .mapToPair(new PairFunction<String, String, Integer>() {

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

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

    }
}

输出结果

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原文链接:https://blog.csdn.net/sundujing/article/details/51480085

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[这个贴子最后由 flybird 在 2020-03-21 15:15:42 重新编辑]

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