配置 url-pattern 增加需要传递给Spring的扩展名

			
	<servlet>
        <servlet-name>springframework</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
   
    <servlet-mapping>
        <servlet-name>springframework</servlet-name>
        <url-pattern>/welcome.jsp</url-pattern>
        <url-pattern>/welcome.html</url-pattern>
        <url-pattern>*.json</url-pattern>
        <url-pattern>*.xml</url-pattern>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>