struts中用过滤器（Filter）解决数据库中文的问题

在web.xml中加上
<filter>
    <filter-name>Set Character Encoding</filter-name>
    <filter-class>com.huahang.tj.struts.filters.SetCharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>GB2312</param-value>
    </init-param>
    <init-param>
      <param-name>ignore</param-name>
      <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>Set Character Encoding</filter-name>
    <servlet-name>action</servlet-name>
</filter-mapping>
这里会涉及一个Filter,源码如下：
import javax.servlet.*;
import java.io.IOException;

.public class SetCharacterEncodingFilter implements Filter {

    protected String encoding = null;
    protected FilterConfig filterConfig = null;
    protected boolean ignore = true;

    public void destroy() {

        this.encoding = null;
        this.filterConfig = null;

    }

    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
    throws IOException, ServletException {

         if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
                request.setCharacterEncoding(encoding);
        }

         chain.doFilter(request, response);

    }

    public void init(FilterConfig filterConfig) throws ServletException {

    this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }
    protected String selectEncoding(ServletRequest request) {

        return (this.encoding);

    }

加上这个后，在action中就可以直接从form中接收gb2312编码的数据了，返回时自然也是gb2312了