request功能獲取請求頭數據

獲取請求頭數據：request方法

（*重要）String getHeader(String name)：通過請求頭的名稱獲取請求頭的值

Enumeration<String> getHeaderNames():獲取所有的請求頭名稱

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //獲取所有請求頭名稱
        Enumeration<String> headerNames = request.getHeaderNames();
        while (headerNames.hasMoreElements()) {
            String name = headerNames.nextElement();
            //根據名稱獲取請求頭的值
            String value = request.getHeader(name);
            System.out.println(name+"---"+value);
        }

    }