JDBC will set up utf8mb4 in properties

I can write utf8mb4 characters (like 👽💔) to the MySQL db table if I first run the command: SET NAMES 'utf8mb4' COLLATE 'utf8mb4_unicode_ci'

on the connection:

  connection = DriverManager.getConnection(url, prop)
  val config: PreparedStatement = connection.prepareStatement("SET NAMES 'utf8mb4' COLLATE 'utf8mb4_unicode_ci'");
  config.executeUpdate();
  val insert: PreparedStatement = connection.prepareStatement("INSERT INTO test "
    + "(ID, NAME) VALUES (?,?)");
  insert.setInt(1, 20);
  insert.setString(2, "test 👽💔");
  insert .executeUpdate();

      

        
        
        
      

    

However, I need to write a Dataframe in a db using Spark and the API doesn't give me access to the connection. I can only pass the properties that will be used to establish the connection (or pass them by url):

val prop = new Properties()
prop.put("user", username)
prop.put("driver", "com.mysql.cj.jdbc.Driver")
prop.put("characterEncoding", "UTF-8") // doesn't accept utf8mb4
prop.put("connectionCollation", "utf8mb4_unicode_ci")

df.write.mode("overwrite").jdbc(s"jdbc:mysql://$dbUrl/$dbName", dbTable, prop)

      

        
        
        
      

    

And it won't work. I cannot pass utf8mb4 as encoding because Java lib throws an error and these settings prevent my application from crashing, but that saves ??? instead of db instead of symbols. Any idea how to solve this?