How to display a single record from mySQL using Java? [duplicate]

In this code I want to display single record where the input is taken from the user, but it shows "You have an error in your SQL syntax".

import java.sql.*;
import java.util.Scanner;

public class Display {

    public static void main(String[] args) throws ClassNotFoundException{

        try{

            Scanner scan= new Scanner(System.in);
            String driver = "com.mysql.jdbc.Driver", u_name="root", pwd="123456", url="jdbc:mysql://localhost:3306/student";
            Class.forName(driver);
            Connection con=DriverManager.getConnection(url, u_name, pwd);
            if(con!=null)
                System.out.println("Connection Successful!");


            System.out.print("Enter the Enrolment to be Updated: ");
            String en=scan.next();
            String qry="SELECT * FROM studentdb WHERE enrolment = ?";
            PreparedStatement stmt=con.prepareStatement(qry);
            stmt.setString(1, en);

            ResultSet result = stmt.executeQuery(qry);
            result.next();
            System.out.print(result.getString(1)+"\t\t"+result.getString(2));
        }
        catch(SQLException e){
            System.out.println("Error: "+e);            
        }    
    }
}