关于java反射的一些代码

@WebServlet("/ReflectServlet")
public class ReflectServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    @Override
    public void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String method = req.getParameter("method");
        System.out.println(method);
        //实例化Class类对象，servlet在请求时候实例化
        Class<?> clazz = this.getClass();    
        try {
            if (method == null) {
                method="toStart";
                //返回一个方法对象
                Method means = clazz.getMethod(method,HttpServletRequest.class,HttpServletResponse.class);
                //调用方法，传入调用方法的实例，参数列表
                means.invoke(this,req,resp);
            }else {
                //返回一个方法对象
                Method means = clazz.getMethod(method,HttpServletRequest.class,HttpServletResponse.class);
                //调用方法，传入调用方法的实例，参数列表
                means.invoke(this,req,resp);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}