Write a java program which illustrates the concept of function?

Write a java program which illustrates the concept of function?
create or replace function StuFun(a in number, b in number, n1 out number)
return number as n2 number;
begin
n1:=a*b;
n2:=a+b;
return (n2);
end;

import java.sql.*;
import java.io.*;
class FunConcept {
 public static void main(String[] args) {
   try {
    DriverManager.registerDriver(new
    oracle.jdbc.driver.OracleDriver());
  System.out.println("DRIVERS LOADED...");
    Connection con =
    DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:
     BudDinu " , "scott " , "tiger ");
     System.out.println("CONNECTION OBTAINED...");
     DataInputStream dis = new DataInputStream(System.in);
     System.out.println("ENTER FIRST NUMBER : ");
     String s1 = dis.readLine();
     System.out.println("ENTER SECOND NUMBER : ");
     String s2 = dis.readLine();
     int n1 = Integer.parseInt(s1);
     int n2 = Integer.parseInt(s2);
     CallableStatement cs = con.prepareCall("{?=call ArthFun (?,?,?)}");
     cs.setInt(2, n1);
     cs.setInt(3, n2);
     cs.registerOutParameter(1, Types.INTEGER);
     cs.registerOutParameter(4, Types.INTEGER);
     cs.execute();
     int res = cs.getInt(1);
     int res1 = cs.getInt(4);
     System.out.println("SUM OF THE NUMBERS : " + res);
     System.out.println("MULTIPLICATION OF THE NUMBERS : " + res1);
    } catch (Exception e) {
     e.printStackTrace();
    }
   } // main
  } // FunConcept