Itext Java 11: Illegal reflective access by com.itextpdf.io.source.ByteBufferRandomAccessSource$1

Question

Recently upgraded to Java 11 and began performing a regression check. Currently get an Illegal reflective access error when trying to call com.itextpdf.text.pdf.PdfReader.close. Currently on Itext version 5.5.13 but also tried on itext 7.0.0 and had same issue.

Does anyone have any suggestions on how to fix compatibility issues between Java-11 and Itext?

WARNING: An illegal reflective access operation has occurred WARNING: Illegal reflective access by com.itextpdf.io.source.ByteBufferRandomAccessSource$1 (file:...repository/com/itextpdf/io/7.0.0/io-7.0.0.jar) to method java.nio.DirectByteBuffer.cleaner() WARNING: Please consider reporting this to the maintainers of com.itextpdf.io.source.ByteBufferRandomAccessSource$1 WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations WARNING: All illegal access operations will be denied in a future release

Have you tried it on the latest iText version (which is 7.1.4 as of today)?. I believe similar issue was encountered for the Java 9, and I think it was fixed. — Yulian Gaponenko, Nov 14 '18 at 13:47
And if you find a solution, can you submit a pull request for iText 7? That would be great! We won't update it for iText 5 though because it is end-of-life. — Amedee Van Gasse, Nov 14 '18 at 13:48

score 9 · Accepted Answer · answered Nov 14 '18 at 19:16

While I second the comments encouraging you to debug the code and find the root cause (and then submit a pull request), or creating an issue in iText Jira if you are a customer with a support contract (which would raise the priority of the issue), here is a workaround suggestion (that I haven't tested, but I chances are it will work):

Use PdfReader and PdfWriter constructors that accept InputStream and OutputStream, respectively. In this case the code causing the problem should not be invoked. Same thing for all the other cases in which iText interacts with your file system - wrap everything into InputStream/OutputStream, or deal with byte[] arrays.

So this line:

new PdfDocument(new PdfReader(inFilePath), new PdfWriter(outFilePath))

becomes this one:

new PdfDocument(new PdfReader(new FileInputStream(inFilePath)), 
                new PdfWriter(new FileOutputStream(outFilePath)))

You might also want to wrap the streams into BufferedInputStream/BufferedOutputStream.

Similarly, when dealing with PdfFontFactory, use methods that accept byte[] instead of String representing file path and so on.

Wrapping the PdfWriter and PdfReader Strings in new FileOutputStreams FileInputStreams did fix it. — D. Millard, Nov 15 '18 at 10:19
changing from PdfReader(String path) to PdfReader(InputStream is) fixed it — jhuamanchumo, Mar 11 '21 at 05:07

score 1 · Answer 2 · answered Nov 14 '18 at 13:58

If you're curious what is the Illegal Reflective Access is all about, please refer here: what is an illegal reflective access

This particular warning comes from this class:

https://github.com/itext/itext7/blob/develop/io/src/main/java/com/itextpdf/io/source/ByteBufferRandomAccessSource.java

From this particular method:

private static boolean clean(final java.nio.ByteBuffer buffer) {
    if (buffer == null || !buffer.isDirect())
        return false;

    Boolean b = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
        public Boolean run() {
            Boolean success = Boolean.FALSE;
            try {
                // java 9
                if (UNMAP_SUPPORTED)
                    CLEANER.freeBuffer(buffer.toString(), buffer);
                // java 8 and lower
                else {
                    Method getCleanerMethod = buffer.getClass().getMethod("cleaner", (Class<?>[]) null);
                    getCleanerMethod.setAccessible(true);
                    Object cleaner = getCleanerMethod.invoke(buffer, (Object[]) null);
                    Method clean = cleaner.getClass().getMethod("clean", (Class<?>[]) null);
                    clean.invoke(cleaner, (Object[]) null);
                }
                success = Boolean.TRUE;
            } catch (Exception e) {
                // This really is a show stopper on windows
                Logger logger = LoggerFactory.getLogger(ByteBufferRandomAccessSource.class);
                logger.debug(e.getMessage());
            }
            return success;
        }
    });

    return b;
}

This line exactly:

getCleanerMethod.setAccessible(true);

As long as this warning does not prevent iText from working as expected, I think the best you can do is to submit an issue/PR to iText team and wait for the proper fix to be available.

Unfortunately the PdfDocument object appears to not close the document. As also seen during debugging as couldn't manually delete the file also due to itext still having hold of the pdf. — D. Millard, Nov 14 '18 at 14:19
Then it's a major bug. You probably want to debug the iText flow itself to find out the root cause. Simple warning should not break such things as resource closing. — Mikhail Kholodkov, Nov 14 '18 at 15:09
Shouldn't the code go through the "`// java 9`" branch rather than the "`// java 8 and lower`"? — Holger, Nov 15 '18 at 22:50

Itext Java 11: Illegal reflective access by com.itextpdf.io.source.ByteBufferRandomAccessSource$1

2 Answers2

Linked