I have a system made for my company and together I have the new website. I can log into the system normally with the accounts registered in the database, but when I insert a filter in the servlet, I get the message:
java.lang.ClassCastException: java.lang.String can not be cast to UTIL.Username
If you delete the filter, the system works normally. The filter I am using is to prevent system pages from being accessed via url, so it is always redirected to login.jsp .
Follow the code.
FiltroSeguranca.java
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
public class FiltroSeguranca implements Filter {
public void init(FilterConfig config) throws ServletException {
}
public void doFilter(ServletRequest req, ServletResponse res,
FilterChain chain) throws IOException, ServletException {
HttpSession session = ((HttpServletRequest) req).getSession();
Usuario usuario = (Usuario) session.getAttribute("name");
if (usuario == null) {
session.setAttribute("msg", "Você não está logado no sistema!");
((HttpServletResponse) res).sendRedirect("login.jsp");
} else {
chain.doFilter(req, res);
}
}
public void destroy() {
}
}
web.xml :
<servlet>
<servlet-name>LoginServlet</servlet-name>
<servlet-class>UTIL.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/LoginServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<filter>
<filter-name>Filtro Seguranca</filter-name>
<filter-class>UTIL.FiltroSeguranca</filter-class>
</filter>
<filter-mapping>
<filter-name>Filtro Seguranca</filter-name>
<url-pattern>/GrantedAccess.jsp</url-pattern>
<url-pattern>/Cadastro.jsp</url-pattern>
</filter-mapping>
UPDATED
Servlet login
public class LoginServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String n = request.getParameter("username");
String p = request.getParameter("userpass");
HttpSession session = request.getSession(false);
if (session != null) {
session.setAttribute("name", n);
}
if (LoginDao.validate(n, p)) {
RequestDispatcher rd = request.getRequestDispatcher("GrantedAccess.jsp");
rd.forward(request, response);
} else {
out.print("<p style=\"color:red\">Sorry username or password error</p>");
RequestDispatcher rd = request.getRequestDispatcher("index.jsp");
rd.include(request, response);
}
out.close();
}
}
LOGIN FORM
<div id="conteudo" class="animated fadeIn">
<div id="raside">
<div class="animated flash">
<h1>
<form action="LoginServlet" method="post">
LOGIN <input autofocus type="text" name="username" required>
SENHA <input type="password" name="userpass" required>
<input type="submit" value="AUTENTICAR">
</form>
</h1>
</div>
</div>
</div>