Java EE 8 Design Patterns and Best Practices

Implementing LogBrowserFilter

The implementation of LogBrowserFilter is as follows:

import org.apache.logging.log4j.LogManager;import org.apache.logging.log4j.Logger;import javax.servlet.*;import javax.servlet.annotation.WebFilter;import javax.servlet.http.HttpServletRequest;import java.io.IOException;@WebFilter(filterName = "LogBrowser",urlPatterns = "/*")public class LogBrowserFilter implements Filter {    private static Logger logger = LogManager.getLogger(LogBrowser.class);    public void destroy() {    }    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {        //Get userAgent that contain browse informations.        String userAgent = ((HttpServletRequest)req).getHeader("User-Agent");