通过org.springframework.web.filter.CharacterEncodingFilter定义Spring web请求的编码

通过类org.springframework.web.filter.CharacterEncodingFilter，定义request和response的编码。具体做法是，在web.xml中定义一个Filter，如下：

    <filter>
        <description>字符集过滤器</description>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <description>字符集编码</description>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
        <init-param>
            <param-name>forceEncoding</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

CharacterEncodingFilter类具有encoding和forceEncoding两个属性，其中encoding是表示设置request的编码，forceEncoding表示是否同时设置response的编码。