<!-- 编码过滤器 -->
  <filter>
    <filter-name>CharacterEncodingFilter</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>
    <!-- 开启强制编码才能过滤GET/POST请求 -->
    <init-param>
      <param-name>forceRequestEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
    <init-param>
      <param-name>forceResponseEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>
  <!-- url-pattern与springmvc一致 -->
  <filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>*.do</url-pattern>
  </filter-mapping>