dispatherServlet拦截所有请求，但是不拦截JSP和其他配置的servelt

不是顺序问题，是就不拦截Servlet

不是load-on-startup启动先后顺序问题，是就是不拦截Servlet。

SpringMVC默认用的是第二个

//<url-pattern>/*</url-pattern>会拦截JSP，静态文件，不拦截Servlet，拦截陌生URL
//<url-pattern>/</url-pattern>拦截静态文件，不拦截JSP和Servlet，拦截陌生URL
public class MyDispatcherServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println(req.getRequestURI());
    }
}

<servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>servlet.MyDispatcherServlet</servlet-class>
    <load-on-startup>-1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/*</url-pattern>
</servlet-mapping>
<servlet>
    <servlet-name>JsonServlet</servlet-name>
    <servlet-class>servlet.JsonServlet</servlet-class>
    <load-on-startup>10</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>JsonServlet</servlet-name>
    <url-pattern>/getJson</url-pattern>
</servlet-mapping>