RowMapper is an interface that is provided by the Spring JDBC. This is used to map a row with a Java object and to fetch data from the database. It uses the query() function of the JdbcTemplate class. Let's create a RowMapper interface named UserRowMapper.kt.

Here is the code of this interface:

class UserRowMapper : RowMapper<UserModel> {

    @Throws(SQLException::class)
    override fun mapRow(row: ResultSet, rowNumber: Int): UserModel? {
        return UserModel(row.getInt("id"),
                row.getString("name"),
                row.getString("email"),
                row.getString("contact_number"))
    }
}

In this code, we extended RowMapper<UserModel> and overrode the mapRow where we return the UserModel.