to john

filter example

package servlets;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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;

@WebFilter("/")
public class NoRepeat implements Filter{

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {

		req = (HttpServletRequest) request;
		res = (HttpServletResponse) response;
		
		List<String> nomes = (ArrayList<String>) req.getSess.getAttribute("nomes");
		
		if(nomes == null) {
			nomes = new ArrayList<String>();
		}
		
		nomes.add((String)req.getAttribute("nome"));
		req.getSession().setAttribute("nomes", nomes);
		
		chain.doFilter(req, res);
		
	}

	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub
		
	}

}