我正在尝试使用JasperReports生成PDF文件，但是无论我如何尝试，它都给了我NullPointerException。

https://community.jaspersoft.com/questions/520803/getting-null-pointer-exception-fillreport

试图看那里，并更改了jasper属性文件，但是它什么也没做，而且我仍然遇到相同的错误。

尝试了绝对路径，相对路径，将资源作为流获取，什么都没有

这是我用来生成报告的代码

public String generateInvoiceFor (Reservation reservation) throws JRException {

        JasperReport jasperReport = JasperCompileManager.compileReport("I:\\anoranzaHopefullyFinal\\src\\main\\resources\\jasper\\FacturaFinalFinal.jrxml");

        List<Reservation> reservations = reservationService.getall();

        JRBeanCollectionDataSource jrBeanCollectionDataSource = new JRBeanCollectionDataSource(reservations);

        Map<String,Object> parameters = new HashMap<>();

        parameters.put("Idparam",reservation.getId());

        JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport,parameters,jrBeanCollectionDataSource);

        JasperExportManager.exportReportToPdfFile(jasperPrint,"jasper/jasperOutput/Factura.pdf");

        return "Report successfully generated @path= jasper/jasperOutput/";



    }