Combining two Jasper reports

Question

I have a web application with a dropdown from where user could select the type of report viz. report1, report2, report3, etc.

Based on the report selected, a Jasper

Answer 1

You can either merge reports before generating PDFs using JasperPrint or after generating PDFs using iText.

For the JasperPrint solution: you will generate the 2 (or more) JasperPrints then get the content pages and concat them.

JasperPrint jp1 = JasperFillManager.fillReport(url.openStream(), parameters,
                    new JRBeanCollectionDataSource(inspBean));
JasperPrint jp2 = JasperFillManager.fillReport(url.openStream(), parameters,
                    new JRBeanCollectionDataSource(inspBean));

List pages = jp2 .getPages();
for (int j = 0; j < pages.size(); j++) {
    JRPrintPage object = (JRPrintPage)pages.get(j);
    jp1.addPage(object);
}
JasperViewer.viewReport(jp1,false);

For the iText solution after generating the PDFs:

void concatPDFs(List streamOfPDFFiles, OutputStream outputStream, boolean paginate) {

    Document document = new Document();
    try {
      List pdfs = streamOfPDFFiles;
      List readers = new ArrayList();
      int totalPages = 0;
      Iterator iteratorPDFs = pdfs.iterator();

      // Create Readers for the pdfs.
      while (iteratorPDFs.hasNext()) {
        InputStream pdf = iteratorPDFs.next();
        PdfReader pdfReader = new PdfReader(pdf);
        readers.add(pdfReader);
        totalPages += pdfReader.getNumberOfPages();
      }
      // Create a writer for the outputstream
      PdfWriter writer = PdfWriter.getInstance(document, outputStream);

      document.open();
      BaseFont bf = BaseFont.createFont(BaseFont.HELVETICA, BaseFont.CP1252, BaseFont.NOT_EMBEDDED);
      PdfContentByte cb = writer.getDirectContent(); // Holds the PDF
      // data

      PdfImportedPage page;
      int currentPageNumber = 0;
      int pageOfCurrentReaderPDF = 0;
      Iterator iteratorPDFReader = readers.iterator();

      // Loop through the PDF files and add to the output.
      while (iteratorPDFReader.hasNext()) {
        PdfReader pdfReader = iteratorPDFReader.next();

        // Create a new page in the target for each source page.
        while (pageOfCurrentReaderPDF < pdfReader.getNumberOfPages()) {
          document.newPage();
          pageOfCurrentReaderPDF++;
          currentPageNumber++;
          page = writer.getImportedPage(pdfReader, pageOfCurrentReaderPDF);
          cb.addTemplate(page, 0, 0);

          // Code for pagination.
          if (paginate) {
            cb.beginText();
            cb.setFontAndSize(bf, 9);
            cb.showTextAligned(PdfContentByte.ALIGN_CENTER, "" + currentPageNumber + " of " + totalPages, 520, 5, 0);
            cb.endText();
          }
        }
        pageOfCurrentReaderPDF = 0;
      }
      outputStream.flush();
      document.close();
      outputStream.close();
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      if (document.isOpen())
        document.close();
      try {
        if (outputStream != null)
          outputStream.close();
      } catch (IOException ioe) {
        ioe.printStackTrace();
      }
    }
  }