import groovy.sql.*;
import java.sql.*;
import oracle.jdbc.driver.OracleTypes;

def url = vars['url']
def user = vars['user']
def password = vars['password']
def driver = vars['driver']
def sql = Sql.newInstance(url, user, password, driver)

try{
    def result = sql.call("{? = call MY_FUNCTION(?,?)}", [Sql.NUMERIC, vars.get('MY_VAR'), 'MY_PARAM']);
} catch (Exception ex) {

    log.error "getMsg: " + ex.getMessage();
}

finally{
    sql.close();
}