Java.io.ioexception: Can't Process Class When Running Proguard In Maven Build Of Android Project

I use a library called iText to write new information to existing PDFs. In order to encrypt PDFs, iText (for Android) uses a library called SpongyCastle which is an Android port of

Solution 1:

The issue is that your re-packaged jar contains *.class files which do not start with the correct magic bytes such a file is expected to start with, i.e. 0xCAFEBABE, cf. this wikipedia article.

It also names the file in question:

__MACOSX/spongycastleseriouslyreduced/org/spongycastle/crypto/._BlockCipher.class

The naming scheme indicates that this indeed is not a *.class file at all but instead a metafile added by some Mac zip program. Proguard does not know such Mac specific stuff and, therefore, falls.

Thus, when you rezip the file, you have to take care that you do not add such Mac specific stuff. This can be done by e.g. using the Java SDK jar utility or a non-Mac zip utility.