Convert Spark Dataframe Columns to json

dataframejson.scla

import org.apache.spark.sql.SparkSession
import org.apache.spark.sql.functions._
  
val spark=SparkSession
    .builder()
    .master("local")
    .appName("local")
    .getOrCreate()
    
import spark.implicits._
val df= List(("A",1),("B",2)).toDF("c1","c2")
df.select(to_json(struct($"c1",$"c2")).as("new")).show()

//+-----------------------+
//|new|
//+-----------------------+
//|      {"c1":"A","c2":1}|
//|      {"c1":"B","c2":2}|
//+-----------------------+