Instrução de conexão ao Banco de Dados no web.xml

Boa tarde, amigos!

Como faço a conexão do banco de dados no web.xml, uma vez que quero que o meu banco seja carregado apenas uma vez?

tenho o código de um servlet que acessa o banco de dados para inclusão:

RegistroAcessoBD

import javax.servlet.<em>;

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

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

import java.util.</em>;

import java.sql.*;

public class RegistroAcessoBD extends HttpServlet {

private String firstName = “”;

private String lastName = “”;

private String userName = “”;

private String password = “”;

private String id = “”;

public void init() {

try {

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

System.out.println(“JDBC driver loaded”);

}

catch (ClassNotFoundException e) {

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

}

}

/*<em>Process the HTTP Get request</em>/

public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

sendPageHeader(response);

sendRegistrationForm(request, response, false);

sendPageFooter(response);

}

/*<em>Process the HTTP Post request</em>/

public void doPost(HttpServletRequest request,

HttpServletResponse response)

throws ServletException, IOException {

sendPageHeader(response);

id=request.getParameter("id");
firstName = request.getParameter("firstName");
lastName = request.getParameter("lastName");
userName = request.getParameter("userName");
password = request.getParameter("password");

boolean error = false;
String message = null;
try {
  Connection con = DriverManager.getConnection("jdbc:mysql://localhost/grupo07","root","admin");
  System.out.println("got connection");

  Statement s = con.createStatement();

  String sql = "SELECT UserName FROM Users" +
    " WHERE userName='" + userName + "'";
  ResultSet rs = s.executeQuery(sql);
  if (rs.next()) {
    rs.close();
    message = "Este username <B>" + userName +     "</B> já existe. Por favor, utilize outro nome.";
    error = true;
  }
  else {
    rs.close();
    sql = "INSERT INTO Users" +
      " (FirstName, LastName, UserName, Password, id)" +
      " VALUES" +
      " ('" +   (firstName) + "'," +
      " '" +   (lastName) + "'," +
      " '" +   (userName) + "'," +
      " '" +   (password) + "'," +
      " '" +   (id) + "')";
    int i = s.executeUpdate(sql);
    if (i==1) {
      message = "Usuário adicionado com SUCESSO!!!";
    }
  }
  s.close();
  con.close();
}
catch (SQLException e) {
  message = "Error." + e.toString();
  error = true;
}
catch (Exception e) {
  message = "Error." + e.toString();
  error = true;
}
if (message!=null) {
  PrintWriter out = response.getWriter();
  out.println("<B>" + message + "</B><BR>");
  out.println("<HR><BR>");
}
if (error==true)
  sendRegistrationForm(request, response, true);
else
  sendRegistrationForm(request, response, false);
sendPageFooter(response);

}

/**

Send the HTML page header, including the title
and the tag
*/
private void sendPageHeader(HttpServletResponse response)
throws ServletException, IOException {
response.setContentType(“text/html”);
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println(“Página de Registro de Acesso”);
out.println("");
out.println("");
out.println("");
}

/**

Send the HTML page footer, i.e. the
and the
*/
private void sendPageFooter(HttpServletResponse response)
throws ServletException, IOException {
PrintWriter out = response.getWriter();
out.println("");
out.println("");
out.println("");
}

/**Send the form where the user can type in

the details for a new user
*/
private void sendRegistrationForm(HttpServletRequest request,
HttpServletResponse response, boolean displayPreviousValues)
throws ServletException, IOException {

PrintWriter out = response.getWriter();
out.println("<BR><H2>Página de Registro de Acesso</H2>");
out.println("<BR>Por favor, entre com os dados do usuário.");
out.println("<BR>");
out.println("<BR><FORM METHOD=POST>");
out.println("<TABLE>");
out.println("<TR>");
out.println("<TD>First Name</TD>");
out.print("<TD><INPUT TYPE=TEXT Name=firstName");

if (displayPreviousValues)
  out.print(" VALUE=\"" + (firstName) + "\"");

out.println("></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Last Name</TD>");
out.print("<TD><INPUT TYPE=TEXT Name=lastName");

if (displayPreviousValues)
  out.print(" VALUE=\"" + (lastName) + "\"");

out.println("></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>User Name</TD>");
out.print("<TD><INPUT TYPE=TEXT Name=userName");

if (displayPreviousValues)
  out.print(" VALUE=\"" + (userName) + "\"");
out.println("></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Password</TD>");
out.print("<TD><INPUT TYPE=PASSWORD Name=password");

if (displayPreviousValues)
  out.print(" VALUE=\"" + (password) + "\"");

if (displayPreviousValues)
  out.print(" VALUE=\"" + (id) + "\"");

out.println("></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD>Id</TD>");
out.print("<TD><INPUT TYPE=TEXT Name=id");

out.println("></TD>");
out.println("</TR>");
out.println("<TR>");
out.println("<TD><INPUT TYPE=RESET value='Limpar'></TD>");
out.println("<TD><INPUT TYPE=SUBMIT value='Cadastrar'></TD>");
out.println("</TR>");
out.println("</TABLE>");
out.println("</FORM>");
out.println("<BR>");
out.println("<BR>");

}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?> ConexaoBanco ConexaoBanco RegistroAcessoBD RegistroAcessoBD DataViewerServlet DataViewerServlet SearchServletSearchServletDeleteServletDeleteServlet UpdateServlet UpdateServlet RegistroAutorBDRegistroAutorBDListaAutorServletListaAutorServletPesquisaAutorServletPesquisaAutorServletDeleteAutorServletDeleteAutorServletUpdateAutorServletUpdateAutorServletRegistroEditoraBDRegistroEditoraBD ConexaoBanco /ConexaoBanco RegistroAcessoBD /RegistroAcessoBD DataViewerServlet /DataViewerServlet SearchServlet /SearchServlet DeleteServlet /DeleteServlet UpdateServlet /UpdateServlet RegistroAutorBD/RegistroAutorBDListaAutorServlet/ListaAutorServletPesquisaAutorServlet/PesquisaAutorServlet DeleteAutorServlet /DeleteAutorServlet UpdateAutorServlet /UpdateAutorServlet RegistroEditoraBD /RegistroEditoraBD 30 principal.html

grato pela atenção.

Girréis!

2 Respostas

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