SpringMVC_编码过滤器

通过过滤器统一请求与响应的编码格式：

    <!--字符编码过滤器-->
    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <!--设置编码格式-->
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <!--对所有请求都生效-->
        <url-pattern>/*</url-pattern>
    </filter-mapping>