过滤器处理接受参数字符乱码问题

Filter： //接受字符转码        String charset = config.getInitParameter("charset");        if(charset == null){            charset = "UTF-8";        }        request.setCharacterEncoding(charset);web.xml: <filter>        <filter-name>LoginFilter</filter-name>        <filter-class>com.lxj.filter.LoginFilter</filter-class>        <init-param>            <param-name>charset</param-name>            <param-value>UTF-8</param-value>        </init-param>    </filter>    <filter-mapping>        <filter-name>LoginFilter</filter-name>        <url-pattern>/*</url-pattern>    </filter-mapping>