Java合并两个Jasper Report

Question

我用jasper report创建了两个报告jrxml。 在我的Java程序中，我将两个报表与iText合并为一个PDF。 问题在于pdf仅包含一份报告和空白页。 我也做过这一证明：在我的Java程序创建报告中，一个创建报告二，合并，而我看到pdf containsig在我的Java程序创建报告中，仅报告一个加空白页，然后在创建报告一中，合并，我看到pdf仅包含报告报告两个加空白页

我必须同时获得两个报告的pdf有人帮助我解决问题吗？

提前致谢

附上我的Java程序的代码：

@Name("pdfFactory")
public class PdfScalareFactory {

    private static final String JASPER_FILE_MOVIMENTI = "scalarePdf/pdf_movimenti.jrxml";
    private static final String JASPER_FILE_SCALARE = "scalarePdf/pdf_scalare.jrxml";

    @SuppressWarnings("rawtypes")
    public byte[] rawPdf(BeScalare beScalare, String codTabulato, String output) throws JRException, IOException {

        JRBeanArrayDataSource dataSource = new JRBeanArrayDataSource(new Object[]{beScalare}); 

        //report's list
        List<byte[]> pdfFilesAsByteArray = new ArrayList<byte[]>();

        //Report one
        Class cScalare = this.getClass();
        ClassLoader clScalare = cScalare.getClassLoader();
        InputStream isScalare = clScalare.getResourceAsStream(JASPER_FILE_SCALARE);
        JasperDesign jasDesignScalare = JRXmlLoader.load(isScalare);
        //compile report one
        JasperReport reportScalare = JasperCompileManager.compileReport(jasDesignScalare);      
        //parameters report one
        Map<String, Object> paramScalare = new HashMap<String, Object>();
        JRBeanCollectionDataSource itemsScalareSaldiPerValuta = new JRBeanCollectionDataSource(beScalare.getLstBeScalareSaldiPerValuta());
        paramScalare.put("scalareSaldiPerValuta", itemsScalareSaldiPerValuta);
        //fill report one
        JasperPrint jasperPrintScalare = JasperFillManager.fillReport(reportScalare, paramScalare, dataSource);
        pdfFilesAsByteArray.add(JasperExportManager.exportReportToPdf(jasperPrintScalare));

        //Report two
        Class c = this.getClass();
        ClassLoader cl = c.getClassLoader();
        InputStream is = cl.getResourceAsStream(JASPER_FILE_MOVIMENTI);
        JasperDesign jasDesign = JRXmlLoader.load(is);
        //compile report two
        JasperReport reportMovimenti = JasperCompileManager.compileReport(jasDesign);
        //parameters report two
        Map<String, Object> paramMovimenti = new HashMap<String, Object>();
        BufferedImage imgNumeroVerde = ImageIO.read(getClass().getResource("/scalarePdf/headphones.png"));
        paramMovimenti.put("numeroVerde", imgNumeroVerde);
        BufferedImage imgInternet = ImageIO.read(getClass().getResource("/scalarePdf/internet.png"));
        paramMovimenti.put("internet", imgInternet);        
        JRBeanCollectionDataSource itemsScalareMovimenti = new JRBeanCollectionDataSource(beScalare.getLstBeScalareMovimenti());
        paramMovimenti.put("scalareMovimenti", itemsScalareMovimenti);
        //fill report two
        JasperPrint jasperPrintMovimenti = JasperFillManager.fillReport(reportMovimenti, paramMovimenti, dataSource);
        pdfFilesAsByteArray.add(JasperExportManager.exportReportToPdf(jasperPrintMovimenti));

        //merge the two reports in one
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        Document document = null;
        PdfCopy writer = null;
        for (byte[] pdfByteArray : pdfFilesAsByteArray) {

            try {
                PdfReader reader = new PdfReader(pdfByteArray);
                int numberOfPages = reader.getNumberOfPages();

                if (document == null) {
                    document = new Document(reader.getPageSizeWithRotation(1));
                    writer = new PdfCopy(document, outStream); // new
                    document.open();
                }
                PdfImportedPage page;
                for (int i = 0; i < numberOfPages;) {
                    ++i;
                    page = writer.getImportedPage(reader, i);
                    writer.addPage(page);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
        }
        document.close();
        outStream.close();
        return outStream.toByteArray();
    }
}

Answer 1

问题出在数据源中，而不是合并中。 您为两个报表都创建了一个数据源，但是第一个报表将使用它，然后第二个报表的数据源末尾带有指针。

您可以使用JRBeanArrayDataSource它实现JRRewindableDataSource这样你就可以调用moveFirst()方法的第一个位置返回数据源指针：

//Report two
dataSource.moveFirst();

或者，您可以再次为第二个报告创建数据源：

//Report two
dataSource = new JRBeanArrayDataSource(new Object[]{beScalare}); 

注意：但是， 正如评论中的安塔拉伦所说，使用JRPdfExporter和List<JasperPrint>实例作为输入来合并两个或更多个Jasper报告更为容易。