Java'da şu hatayı nasıl çözerim ?

package kayitol;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class kayitservlet
 */
@WebServlet("/kayitservlet")
public class kayitservlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

       

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    String uid = request.getParameter("id");
    String uisim = request.getParameter("isim");
    String uemail = request.getParameter("email");
    String usifre = request.getParameter("sifre");
    RequestDispatcher dispatcher = null;
    Connection con = null;
    try  {
        Class.forName("com.mysql.cj.jdbc.Driver");
        con = DriverManager.getConnection("jdbc:mysql://localhost:3306/siyar","root","jacobo93");
        PreparedStatement pst= con.
                prepareStatement("insert into users(uid,uisim,uemail,usifre) values(?,?,?,?)" );
    pst.setString(1, uid);
    pst.setString(2, uisim);
    pst.setString(3, uemail);
    pst.setString(4, usifre);
    int rowCount = pst.executeUpdate();
    dispatcher = request.getRequestDispatcher("kayit.jsp");
    if (rowCount > 0) {
        request.setAttribute("status","success");
    } else {
        request.setAttribute("status","failed");
    }
    dispatcher.forward(request, response);
    } catch(Exception e) {
        e.printStackTrace();
    }finally {
        try {
            con.close();
        }catch (SQLException e) {
            e.printStackTrace();
            
        }
        
    }
    }

}