java.sql.SQLException : Parameter index out of range (1 > number of parameters, 即 0)。为什么会发生这种异常以及如何解决

Question

/*
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 */
package bean;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;
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;

/**
 *
 * @author hp
 */
@WebServlet(name = "Getdetails", urlPatterns = {"/Getdetails"})
public class Getdetails extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {
            /* TODO output your page here. You may use following sample code. */
            Connection con = null;
            PreparedStatement ps = null;
            Statement st = null;
            ResultSet rs = null;
            String debitcard = new String();
            String debitcardno = new String();
            String accountno = new String();
            String account = new String();
            String cvv = new String();
            String pin = new String();

            try {
                Class.forName("com.mysql.jdbc.Driver");
                con = DriverManager.getConnection("jdbc:mysql://localhost:3306/bussinesssolutions?zeroDateTimeBehavior=convertToNull", "root", "root");
                ps = con.prepareStatement("select card.debitcardno, card.accountnno, card.cvv, card.pin from card inner join regsiter on card.edebitcardno = regsiter.debitcardno");
                ps.setString(1, debitcard);
                ps.setString(2, account);
                ps.setString(3, cvv);
                ps.setString(4, pin);
                rs = ps.executeQuery();
                debitcardno = rs.getString("debitcardno");
                accountno = rs.getString("accountno");
                cvv = rs.getString("cvv");
                pin = rs.getString("pin");

                request.getSession().setAttribute("debitcardno", debitcardno);
                request.getSession().setAttribute("accountno", accountno);
                request.getSession().setAttribute("cvv", cvv);
                request.getSession().setAttribute("pin", pin);
                RequestDispatcher rd = request.getRequestDispatcher("Getdetails");
                rd.forward(request, response);
            } catch (ClassNotFoundException | SQLException | ServletException | IOException e) {
                out.print(e);
            } finally {
                if (con != null) {
                    try {
                        con.close();
                    } catch (SQLException ex) {
                        Logger.getLogger(Bankdetails.class.getName()).log(Level.SEVERE, null, ex);
                    }
                }
                try {
                    ps.close();
                    st.close();
                } catch (SQLException ex) {
                    Logger.getLogger(Bankdetails.class.getName()).log(Level.SEVERE, null, ex);
                }
                try {
                    rs.close();
                } catch (SQLException ex) {
                    Logger.getLogger(Bankdetails.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        `return` "Short description";
    }// </editor-fold>

}

我收到上述异常。不知道为什么会出现这种异常以及如何解决。我想从上述详细信息的数据库中获取详细信息，但代码中可能存在一些错误，导致它没有发生

Answer 1

ps = con.prepareStatement("select card.debitcardno, card.accountnno, card.cvv, " + 
    "card.pin from card inner join regsiter on card.edebitcardno = regsiter.debitcardno");

此语句中没有 ? 参数。以下任何一个都不起作用。

ps.setString(1, debitcard);
ps.setString(2, account);
ps.setString(3, cvv);
ps.setString(4, pin);

您需要实际提供要分配的参数。

ps = con.prepareStatement("select card.debitcardno, card.accountnno, card.cvv, " + 
    "card.pin from card inner join regsiter on " + 
    "card.edebitcardno = regsiter.debitcardno " + 
    "where card.debitcardno=? AND card.accountno=? AND card.cvv=? AND card.pin=?");