SSM项目引入文件失败

        <mvc:resources mapping="/styles/**"
        location="/css/"/>
        <mvc:resources mapping="/images/**"
        location="/images/"/>
<mvc:resources mapping="/js/**" location="/js/"/>
        <mvc:default-servlet-handler />   

或者

<servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.css</url-pattern>
    </servlet-mapping> 

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.gif</url-pattern>
    </servlet-mapping> 

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.jpg</url-pattern>
    </servlet-mapping> 

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.js</url-pattern>
    </servlet-mapping>