Question

我有这个servlet：

import DAO.ConexionBDD;
import DAO.Operaciones;
import Modelos.Votante;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Lux
 */
public class CreaVotante 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, SQLException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {
            /* TODO output your page here. You may use following sample code. */
            Votante v=new Votante(request.getParameter("nif"), request.getParameter("clave"));
            Operaciones op=new Operaciones();
            op.registrar(v, Conexion);
                out.println("<html>");
                out.println("<head><title>Title</title></head>");
                out.println("<body>");
                out.println("Hi");
            }
        }

    // <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{
        try {
            processRequest(request, response);
        } catch (SQLException ex) {
            Logger.getLogger(CreaVotante.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /**
     * 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 {
        try {
            processRequest(request, response);
        } catch (SQLException ex) {
            Logger.getLogger(CreaVotante.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

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

    private Connection Conexion;

    public void init() throws ServletException {
 /* Establecemos la conexión, si no existe */
    try{
        ConexionBDD ConexBD=ConexionBDD.GetConexion();
        Conexion=ConexBD.GetCon();
    }
    catch(ClassNotFoundException cnfe){
    }
    catch(SQLException sqle){
    }
 }
}

当我打电话给op.registrar（v，Conexion）时;它停止工作，不打印调用下的内容但是当我没有那个电话时它会打印出所有内容。这是函数注册商：

public int registrar(Votante _Votante, Connection _Conexion) throws SQLException {
        int resultado;
        String nif=_Votante.getNif();
        String clave=_Votante.getClave();

        try{
            Statement s = _Conexion.createStatement();
            resultado=s.executeUpdate ("INSERT INTO votantes (nif, clave) VALUES ('nif', 'clave')");

        } 
        catch(SQLException SQLE){
            throw new SQLException(SQLE);
        }
        if (resultado==0)throw new SQLException();

        return resultado;
    }

编辑：每当我调用需要连接数据库的函数时，它都不起作用。这是Connection类：

import java.sql.*;
public class ConexionBBDD {
 private static ConexionBBDD UnicaConexion=null;
 private Connection Conex;

 private ConexionBBDD() throws ClassNotFoundException, SQLException{
 Class.forName("com.mysql.jdbc.Driver");
 String connectionUrl = "jdbc:mysql://localhost:3306/bd_votaciones_inn";
 Conex = DriverManager.getConnection(connectionUrl,"root","root");
 }

public synchronized static ConexionBBDD GetConexion() throws ClassNotFoundException, SQLException{
 if(UnicaConexion == null){
 UnicaConexion = new ConexionBBDD();
 }
 return UnicaConexion;
 }

 public Connection GetCon(){
 return Conex;
 }

 public void Destroy() throws SQLException{
 Conex.close();
 }
}

Answer 1

原因似乎是registrar方法抛出异常，该异常会冒泡到doPost或doGet方法。由于processRequest方法没有捕获异常，因此永远不会执行调用registrar之后的行。

您有一些日志语句应包含有关特定错误的更多详细信息。

调用函数时Servlet没有响应

1 个答案: