如何在spring mvc中的excelBuilder类中自动服务

Question

public class ExcelBuilder extends AbstractExcelView {

        @Autowired
        EkamtayinService ekamtayinService;//ekamtayin service is null

        @Override
        protected void buildExcelDocument(Map<String, Object> model, HSSFWorkbook workbook, HttpServletRequest request,
                HttpServletResponse response) throws Exception {
          //...
        }
 }