<filter>
<filter-name>encoding</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encoding</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!--<url-pattern>/*</url-pattern>->/*与/的区别:
/ 不会匹配到*.jsp，即：*.jsp不会进入spring的 DispatcherServlet类 。
/* 会匹配*.jsp，会出现返回jsp视图时再次进入spring的DispatcherServlet 类.
