request功能获取请求头数据

获取请求头数据：request方法

（*重要）String getHeader(String name)：通过请求头的名称获取请求头的值

Enumeration<String> getHeaderNames():获取所有的请求头名称

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取所有请求头名称
        Enumeration<String> headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String name = headerNames.nextElement();
            //根据名称获取请求头的值
            String value = request.getHeader(name);
            System.out.println(name+"---"+value);
        }

    }