request浏览器判断

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        String agent = request.getHeader("User-Agent");
        if (agent.contains("Trident")) {
            response.getWriter().print("不准使用这么垃圾的浏览器");
        } else if (agent.contains("Chrome")) {
            response.getWriter().print("您当前使用的浏览器是谷歌");
        } else if (agent.contains("Firefox")) {
            response.getWriter().print("您当前使用的浏览器是火狐");
        } else {
            response.getWriter().print("其他浏览器");
        }
    }