public class BaseServlet extends HttpServlet{

    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //設定編碼表
        req.setCharacterEncoding("UTF-8");
        resp.setContentType("text/html;charset=UTF-8");
        // 接收引數:
        String methodName = req.getParameter("method");
        //如果method傳遞的引數為null或者為空字串,作出提示
        if(methodName == null || "".equals(methodName)){
            resp.getWriter().println("method引數為null!!!");
            return;
        }
        // 獲得子類的Class物件：
        /**
         * this.class代表載入繼承了這個BaseServlet的class物件
         * */
        Class clazz = this.getClass();
        // 獲得子類中的方法了:
        try {
            Method method = clazz.getMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);
            // 使方法執行,並獲取子類return的字串
            String path = (String)method.invoke(this, req,resp);
            //轉發
            if(path != null){
                req.getRequestDispatcher(path).forward(req, resp);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}