Spark-java相关算子

Spark-java相关算子练习

Transformations算子

package com.cs.java.spark;

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
import org.apache.spark.api.java.function.Function;
import org.apache.spark.api.java.function.VoidFunction;

public class Day01 {
public static void main(String[] args) {
    SparkConf conf = new SparkConf();
    conf.setAppName("day01");
    conf.setMaster("local");
    JavaSparkContext sc = new JavaSparkContext(conf);
    sc.setLogLevel("Error");
    
	。。。
	。。。
	

	}
}

filter-过滤

JavaRDD<String> lines = sc.textFile("./Test_spark/data/words2");
//filter过滤
JavaRDD<String> result = lines.filter(new Function<String, Boolean>() {
    @Override
    public Boolean call(String line) throws Exception {
        return "hello spark".equals(line);
    }
});
result.foreach(new VoidFunction<String>() {
    @Override
    public void call(String s) throws Exception {
        System.out.println(s);
    }
});
sc.stop();

count-计数

//count计数
final long count = result.count();
System.out.println(count);
sc.stop();

map-1:1进出一条数据 单个（个，个）

JavaRDD<String> lines = sc.textFile("./Test_spark/data/words2");
JavaRDD<String> map = lines.map(new Function<String, String>() {