import java.io.IOException;
import java.net.URLDecoder;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

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;

  }

  /**
   * @param request
   *            The servlet request we are processing
   * @param result
   *            The servlet response we are creating
   * @param chain
   *            The filter chain we are processing
   * 
   * @exception IOException
   *                if an input/output error occurs
   * @exception ServletException
   *                if a servlet error occurs
   */
  public void doFilter(ServletRequest request, ServletResponse response,
      FilterChain chain) throws IOException, ServletException {

    // Conditionally select and set the character encoding to be used
    if (ignore || (request.getCharacterEncoding() == null)) {
      String encoding = selectEncoding(request);
      if (encoding != null) {
        request.setCharacterEncoding(encoding);
        HttpServletRequest hr = (HttpServletRequest) request;
        System.out.println(hr.getRequestURI());
        System.out.println(URLDecoder.decode(hr.getRequestURI(),
            "utf-8"));
      }
    }
    chain.doFilter(request, response);
  }

  /**
   * Place this filter into service.
   * 
   * @param filterConfig
   *            The filter configuration object
   */
  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;

  }

  /**
   * @param request
   *            The servlet request we are processing
   */
  protected String selectEncoding(ServletRequest request) {

    return (this.encoding);
  }
}

javadd wrote:
用户绝对要上传中文文件的.