Operator_sample

package com.bjsxt.spark.transformations;

import java.util.ArrayList;
import java.util.List;

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

import scala.Tuple2;

public class Operator_sample {
    public static void main(String[] args) {
        SparkConf conf = new SparkConf();
        conf.setMaster("local");
        conf.setAppName("sample");
        
        JavaSparkContext jsc = new JavaSparkContext(conf);
        JavaRDD<String> lines = jsc.textFile("./words.txt");
        JavaPairRDD<String, Integer> flatMapToPair = lines.flatMapToPair(new PairFlatMapFunction<String, String, Integer>() {
            private static final long serialVersionUID = 1L;

            @Override
            public Iterable<Tuple2<String, Integer>> call(String t)
                    throws Exception {
                List<Tuple2<String,Integer>> tupleList = new ArrayList<Tuple2<String,Integer>>();
                tupleList.add(new Tuple2<String,Integer>(t,1));
                return tupleList;
            }
        });
        JavaPairRDD<String, Integer> sampleResult = flatMapToPair.sample(true,0.3,4);
        sampleResult.foreach(new VoidFunction<Tuple2<String,Integer>>() 
            private static final long serialVersionUID = 1L;

            @Override
            public void call(Tuple2<String, Integer> t) throws Exception {
                System.out.println(t);
            }
        });
        
        jsc.stop();
    }
}