Olá pessoal, estou fazendo uma aplicação LoginServlet para testar a conexão com o banco de dados, mas esta não esta dando certo. Como no NetBeans já faço a conexão automátina do BD e a criação de tabelas na própria ferr…

1o - Para login, vc tem um mecanismo muito eficiente do próprio conteiner JSP/Servler. Pesquise por autentication and autorization; 2o Post seu código para ver a conexão.

Servlet e BD no NetBeans

Ai vai o código que estou usando:

LoginServlet.java
Created on 31 de Maio de 2004, 10:28
*/

package com.mycompany;

import javax.servlet.<em>;

import javax.servlet.http.</em>;

import <a href="http://java.io">java.io</a>.<em>;

import <a href="http://java.net">java.net</a>.</em>;

import java.util.<em>;

import java.sql.</em>;

/**
*

@author Leisley

@version
*/
public class LoginServlet extends HttpServlet {

/** Handles the HTTP <code>GET</code> method.

@param request servlet request
@param response servlet response
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
sendLoginForm(response, false);
}

/** Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.

@param request servlet request

@param response servlet response

*/

private void sendLoginForm(HttpServletResponse response, boolean withErrorMessage)

throws ServletException, IOException {

response.setContentType(“text/html”);
PrintWriter out = response.getWriter();

out.println("<html>");

out.println("<head>");

out.println("<title>Login</title>");

out.println("</head>");

out.println("");

out.println("<center>");

if(withErrorMessage)

out.println(“Login failed. Pleased try again.
”);

out.println("
");

out.println("
<h2>Login Page</h2>");

out.println("
");

out.println("
<FORM METHOD=POST>");

out.println("<TABLE>");

out.println("<TR>");

out.println("<TD>User Name:</TD>");

out.println("<TD></TD>");

out.println("</TR>");

out.println("<TR>");

out.println("<TD>Password:</TD>");

out.println("<TD></TD>");

out.println("</TD>");

out.println("<TR>");

out.println("<TD ALIGN=RIGTH COLSPAN=2>");

out.println("<TD></TD>");

out.println("</TR>");

out.println("</TABLE>");

out.println("</FORM>");

out.println("</CENTER>");

out.println("");

out.println("</html>");

}

/** Handles the HTTP <code>POST</code> method.

@param request servlet request
@param response servlet response
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String userName = request.getParameter(“userName”);
String password = request.getParameter(“password”);
if (login(userName,password)){
RequestDispatcher rd = request.getRequestDispatcher(“AnotherServlet”);
rd.forward(request, response);
}
else{
sendLoginForm(response, true);
}

}

boolean login(String userName, String password){

try{

Class.forName(“com.mysql.jdbc.Driver”).newInstance();

Connection con = DriverManager.getConnection(“jdbc:mysql:JavaWeb”);

System.out.println(“got connection”);

Statement s = con.createStatement();

String sql = “SELECT UserName FROM Users” +

" WHERE UserName=’" + userName + “’” +

“AND Password=’” + password + “’”;

ResultSet rs = s.executeQuery(sql);

if (rs.next()){

rs.close();

s.close();

con.close();

return true;

}

rs.close();

s.close();

con.close();

}

/*  catch (ClassNotFoundException e){

System.out.println(e.toString());

}*/

catch (SQLException e){
    System.out.println(e.toString());
}
    
catch (Exception e){
    System.out.println(e.toString());
}
return false;
}

}

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