code: public static PagingInfo getPageInfos(final HttpServletRequest request, final int defaultPageSize) {
  		PagingInfo info = new PagingInfo();
  		info.setKey(getPageKey(request));
  		info.setUrl(getUrl(request));
  		info.setTotal(getTotal(request));
  		info.setPageIndex(getPageIndex(request));
  		info.setPageSize(getPageSize(request, defaultPageSize));
  		return info;
  	}
docs: 提取分页信息。
  
  @param request
  请求
  @param defaultPageSize
  默认每页记录数
  @return 分页信息