springSecurity之如何添加自定义过滤器

<Http use-expressions="false" entry-point-ref="loginEntryPoint">
  <intercept-url pattern="/user.jsp" access="ROLE_USER,ROLE_ADMIN"/>
  <intercept-url pattern="/admin.jsp" access="ROLE_ADMIN"/>
  <intercept-url pattern="
  public ServletRequestWrapper(httpservletRequest request) {
    super(request);
    requestParam = HttpUtil.getBodyString(request);
    body = requestParam.getBytes(Charset.forName("utf-8"));
  }
  @Override
  public BufferedReader getReader() throws IOException {
    return new BufferedReader(new InputStreamReader(getRequest().getInputStream(), Charset.forName("UTF-8")));
  }
  @Override
  public ServletInputStream getInputStream() throws IOException {
    return new CustomServletInputStream();
  }
  private class CustomServletInputStream extends ServletInputStream {
    private ByteArrayInputStream inputStream = new ByteArrayInputStream(body);
    @Override
    public boolean isFinished() {
      return false;
    }
    @Override
    public boolean isReady() {
      return false;
    }
    @Override
    public void setReadListener(ReadListener listener) {
    }
    @Override
    public int read() throws IOException {
      return inputStream.read();
    }
  }
  public String getRequestParam() {
    return requestParam;
  }
}

public class HttpUtil {
  public static String getBodyString(ServletRequest request) {
    BufferedReader bufferedReader = null;
    InputStream inputStream = null;
    StringBuilder sb = new StringBuilder("");
    try {
      inputStream = request.getInputStream();
      bufferedReader = new BufferedReader(new InputStreamReader(inputStream, Charset.forName("utf-8")));
      String line = "";
      while ((line = bufferedReader.readLine()) != null) {
        sb.append(line);
      }
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      if (bufferedReader != null) {
        try {
          bufferedReader.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
      if (inputStream != null) {
        try {
          inputStream.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
    return sb.toString();
  }
}