Java 类com.itextpdf.text.pdf.PRStream 实例源码

/**
 * @see #testExtractImageLikeSteveB()
 */
private static List<BufferedImage> FindImages(PdfReader reader, PdfDictionary pdfPage) throws IOException
{
    List<BufferedImage> result = new ArrayList<>(); 
    Iterable<PdfObject> imgPdfObject = FindImageInPDFDictionary(pdfPage);
    for (PdfObject image : imgPdfObject)
    {
        int xrefIndex = ((PRIndirectReference)image).getNumber();
        PdfObject stream = reader.getPdfObject(xrefIndex);
        // Exception occurs here :
        PdfImageObject pdfImage = new PdfImageObject((PRStream)stream);
        BufferedImage img = pdfImage.getBufferedImage();

        // Do something with the image
        result.add(img);
    }
    return result;
}

private void unpack(Set<PdfDictionary> dictionaries) throws TaskIOException {
    for (PdfDictionary dictionary : dictionaries) {
        PdfName type = dictionary.getAsName(PdfName.TYPE);
        if (PdfName.F.equals(type) || PdfName.FILESPEC.equals(type)) {
            PdfDictionary ef = dictionary.getAsDict(PdfName.EF);
            PdfString fn = dictionary.getAsString(PdfName.F);
            if (fn != null && ef != null) {
                PRStream prs = (PRStream) PdfReader.getPdfObject(ef.get(PdfName.F));
                if (prs != null) {
                    File tmpFile = copyToTemporaryFile(prs);
                    outputWriter.addOutput(file(tmpFile).name(fn.toUnicodeString()));
                }
            }
        }
    }
}

private File copyToTemporaryFile(PRStream prs) throws TaskIOException {
    File tmpFile = createTemporaryBuffer();
    LOG.debug("Created output temporary buffer {}", tmpFile);

    ByteArrayInputStream inputStream = null;
    try {
        inputStream = new ByteArrayInputStream(PdfReader.getStreamBytes(prs));
        FileUtils.copyInputStreamToFile(inputStream, tmpFile);
        LOG.debug("Attachment unpacked to temporary buffer");
    } catch (IOException e) {
        throw new TaskIOException("Unable to copy attachment to temporary file.", e);
    } finally {
        IOUtils.closeQuietly(inputStream);
    }
    return tmpFile;
}