sparksql load/save

java

 public class LoadAndSaveDemo {
     private static SparkConf conf = new SparkConf().setAppName("loadandsavedemo").setMaster("local");
     private static JavaSparkContext jsc = new JavaSparkContext(conf);
     private static SparkSession session = new SparkSession(jsc.sc());

     public static void main(String[] args) {

         // 读取,不指定数据类型则默认是parquet
         Dataset<Row> dataset = session.read().load("./src/main/java/cn/tele/spark_sql/dataset/users.parquet");

         dataset.show();

         dataset.createOrReplaceTempView("users");

         // 保存,指定目录,不指定则默认保存的类型是parquet
         // session.sql("select * from
         // users").write().save("./src/main/java/cn/tele/spark_sql/dataset/users");

         // 或者
         // dataset.select(dataset.col("")).write().save("");

         // 读取json
         Dataset<Row> json = session.read().format("json")
                 .load("./src/main/java/cn/tele/spark_sql/dataset/students.json");
         json.show();

 //        json.select(json.col("name")).write().format("json").save("./src/main/java/cn/tele/spark_sql/dataset/students");

         // 指定savemodel
         json.select(json.col("name")).write().format("json").mode(SaveMode.Append)
                 .save("./src/main/java/cn/tele/spark_sql/dataset/students");

         session.stop();
         jsc.close();
     }
 }

scala

 object LoadAndSaveDemo {
   def main(args: Array[String]): Unit = {
     val conf = new SparkConf().setAppName("loadandsavedemo").setMaster("local")
     val sc = new SparkContext(conf)
     val sqlContext = new SQLContext(sc)

     /* val df = sqlContext.read.load("./src/main/scala/cn/tele/spark_sql/dataframe/users.parquet")
     df.show()

     df.write.save("./src/main/scala/cn/tele/spark_sql/dataframe/users")*/

     //读取指定格式
     val df = sqlContext.read.format("json").load("./src/main/scala/cn/tele/spark_sql/dataframe/students.json")
     df.write.format("json").mode(SaveMode.Append).save("./src/main/scala/cn/tele/spark_sql/dataframe/students")
   }
 }