spark parquet 从hdfs 上读 和写

import org.apache.spark.SparkConf;import org.apache.spark.api.java.JavaSparkContext;import org.apache.spark.sql.DataFrame;import org.apache.spark.sql.SQLContext;import org.apache.spark.sql.SaveMode;/** * @author Administrator * */public class GenericLoadSave {public static void main(String[] args) {SparkConf conf = new SparkConf() .setAppName("GenericLoadSave").setMaster("local");JavaSparkContext sc = new JavaSparkContext(conf);SQLContext sqlContext = new SQLContext(sc);//parquet 带表结构 ？？？DataFrame usersDF = sqlContext.read().load("hdfs://hadoop1:9000/input/users.parquet");//没有指定format  就是写入到磁盘的数据格式     默认是parquetusersDF.select("name", "favorite_color").write().mode(SaveMode.Overwrite).save("hdfs://hadoop1:9000/output/namesAndFavColors_scala");   DataFrame pDF = sqlContext.read().parquet("hdfs://hadoop1:9000/output/namesAndFavColors_scala");pDF.show();}}