[PDFBOX-3566] ClassCastException in JPEGFactory.createFromImage()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.3
• Fix Version/s: 2.0.4, 3.0.0 PDFBox
• Environment: Linux OS, Java 1.8, Oracle Java Advanced Imaging (JAI) installed.
• Assignee: Tilman Hausherr
• Reporter: ceakki
• Created: 11/Nov/16 09:39
• Updated: 25/Mar/17 18:13
• Resolved: 11/Nov/16 17:06

Description

I was trying to save all the pages from a PDF as images and adding them to a newly created PDF.

PDDocument newDoc = new PDDocument();

PDFRenderer pdfRenderer = new PDFRenderer(oldDoc);

floag width = ...
float height = ...

page.setMediaBox(new PDRectangle(width, height));

newDoc.addPage(page);

PDPageContentStream contents = new PDPageContentStream(newDoc, page);

BufferedImage bufferedImage = pdfRenderer.renderImageWithDPI(0, 200, ImageType.RGB);

PDImageXObject imageXObject = JPEGFactory.createFromImage(newDoc, bufferedImage, 0.75);

contents.drawImage(imageXObject, 0, 0, width, height);

contents.close();

...

Sometimes it's working just fine, sometimes it's trowing a ClassCastException in JPEGFactory.createFromImage:

java.lang.ClassCastException: com.sun.media.imageioimpl.plugins.jpeg.CLibJPEGImageWriteParam cannot be cast to javax.imageio.plugins.jpeg.JPEGImageWriteParam
	at org.apache.pdfbox.pdmodel.graphics.image.JPEGFactory.encodeImageToJPEGStream(JPEGFactory.java:244)
	at org.apache.pdfbox.pdmodel.graphics.image.JPEGFactory.createJPEG(JPEGFactory.java:212)
	at org.apache.pdfbox.pdmodel.graphics.image.JPEGFactory.createFromImage(JPEGFactory.java:175)
	at org.apache.pdfbox.pdmodel.graphics.image.JPEGFactory.createFromImage(JPEGFactory.java:160)
	at com.mimecast.ttpservice.app.jpati.ConvertPDF.saveDoc(ConvertPDF.java:1390)

This is happening in the following code of above mentioned class:

imageWriter = ImageIO.getImageWritersBySuffix("jpeg").next();
...
JPEGImageWriteParam jpegParam = (JPEGImageWriteParam)imageWriter.getDefaultWriteParam();

In my case I can get more than one ImageWritter when calling ImageIO.getImageWritersBySuffix("jpeg") as follows:

com.sun.imageio.plugins.jpeg.JPEGImageWriter
com.sun.media.imageioimpl.plugins.jpeg.CLibJPEGImageWriter

I suspect that sometimes the CLibJPEGImageWriter is returned before JPEGImageWriter, which produces the ClassCastException a bit later.

As I need to keep the JAI installed, is it possible to change the above code to loop through all ImageWriters found in order to pick the one needed by PdfBox?

I would recommend doing something like this:

Iterator<ImageWriter> iterator = ImageIO.getImageWritersBySuffix("jpeg");
while (iterator.hasNext()) {
    ImageWriter foundWriter = iterator.next();

    if (foundWriter instanceof JPEGImageWriter) {
        imageWriter = foundWriter;
        break;
    }
}

if (imageWriter == null) {
    throw new InvalidStateException("No image writer found of JPEGImageWriter type");
}