public class BaseServlet extends HttpServlet{

    @Override

    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

        //设置编码表

        req.setCharacterEncoding("UTF-8");

        resp.setContentType("text/html;charset=UTF-8");

        // 接收参数:

        String methodName = req.getParameter("method");

        //如果method传递的参数为null或者为空字符串,作出提示

        if(methodName == null || "".equals(methodName)){

            resp.getWriter().println("method参数为null!!!");

            return;

        }

        // 获得子类的Class对象：

        /**

         * this.class代表加载继承了这个BaseServlet的class对象

         * */

        Class clazz = this.getClass();

        // 获得子类中的方法了:

        try {

            Method method = clazz.getMethod(methodName, HttpServletRequest.class,HttpServletResponse.class);

            // 使方法执行,并获取子类return的字符串

            String path = (String)method.invoke(this, req,resp);

            //转发

            if(path != null){

                req.getRequestDispatcher(path).forward(req, resp);

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

}