请求解释request.setAttribute(四个参数)

public void findVoteInfo(HttpServletRequest request){

NewsCenterDAO dao = NewsCenterDAO.getNewsCenterDAO();

StringBuffer sql = new StringBuffer("from WebVote order by createDate desc");

Object[] obj = new Object[0];

request.setAttribute(PageUtil.DATANAME, dao.find(PageUtil.getBaseParam(request), sql.toString(), obj));

}