Security Filter

package com.evs.objava33.class18;

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.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet Filter implementation class SecurityFilter
 */
@WebFilter(filterName = "SecurityFilter", urlPatterns = "/*")
public class SecurityFilter implements Filter {

/**
* Default constructor.
*/
public SecurityFilter() {
// TODO Auto-generated constructor stub
}

/**
* @see Filter#destroy()
*/
public void destroy() {
// TODO Auto-generated method stub
}

/**
* @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain)
*/
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {

HttpServletRequest req = (HttpServletRequest) request;
String url = req.getRequestURI();
if (url.indexOf("LoginServlet") == -1) {
String user = (String) req.getSession().getAttribute("user");
if (user == null) {
HttpServletResponse resp = (HttpServletResponse) response;
resp.sendRedirect("LoginServlet?error=1");
return;
}
}

// pass the request along the filter chain
chain.doFilter(request, response);
}

/**
* @see Filter#init(FilterConfig)
*/
public void init(FilterConfig fConfig) throws ServletException {
// TODO Auto-generated method stub
}

}