Spark Row to JSON

Spark 2.1 should have native support for this use case (see #15354).

import org.apache.spark.sql.functions.to_json
df.select(to_json(struct($"c1", $"c2", $"c3")))

I use this command to solve the to_json problem:

output_df = (df.select(to_json(struct(col("*"))).alias("content")))