Operator_takeAndFirst

package com.bjsxt.spark.actions;

import java.util.Arrays;
import java.util.List;

import org.apache.spark.SparkConf;
import org.apache.spark.api.java.JavaRDD;
import org.apache.spark.api.java.JavaSparkContext;
/**
* take
*
* @author root
*
*/
public class Operator_takeAndFirst {
public static void main(String[] args) {
SparkConf conf = new SparkConf();
conf.setMaster("local").setAppName("take");
JavaSparkContext jsc = new JavaSparkContext(conf);
JavaRDD<Tuple2<Integer,String>> parallelize = jsc.parallelize(
Arrays.asList(
new Tuple2<Integer,String>(1,"a"),
new Tuple2<Integer,String>(2,"b"),
new Tuple2<Integer,String>(3,"c"),
new Tuple2<Integer,String>(4,"d")
)
);
List<Tuple2<Integer,String>> take = parallelize.take(2);
for(Tuple2<Integer,String> s:take){
System.out.println(s);
}
jsc.stop();
*/

JavaRDD<String> parallelize = jsc.parallelize(Arrays.asList("a","b","c","d"));
List<String> take = parallelize.take(2);
String first = parallelize.first();
for(String s:take){
System.out.println(s);
}
jsc.stop();
}
}

原文地址:https://www.cnblogs.com/huiandong/p/9194566.html