oglimmer/lunchy

package de.oglimmer.lunchy.web.servlet;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;

import de.oglimmer.lunchy.services.BotDetectionService;
import lombok.extern.slf4j.Slf4j;

@Slf4j
@WebFilter(urlPatterns = { "/", "/index.jsp", "/portal.jsp" })
public class BotFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest httpReq = (HttpServletRequest) request;

        String userAgent = httpReq.getHeader("User-Agent");
        log.trace("UA: " + userAgent);
        
        if (isBot(userAgent)) {
            log.info("Bot found: " + userAgent);
            RequestDispatcher view = httpReq.getRequestDispatcher("/static_portal.html");
            view.forward(request, response);
        } else {
            chain.doFilter(request, response);
        }
    }

    private boolean isBot(String userAgent) {
        return BotDetectionService.INSTANCE.isBot(userAgent);
    }

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void destroy() {
    }

}