Dúvida sobre Design Pattern Filtro [RESOLVIDO]

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;

public class TempoFiltro implements Filter {

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

	@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		long antes = System.currentTimeMillis();
		chain.doFilter(request, response);
		long depois = System.currentTimeMillis() - antes;
		System.out.println("Tempo gasto: " + depois + "ms");
	}

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