Add non-ASCII file names to zip in Java

Question

What is the best way to add non-ASCII file names to a zip file using Java, in such a way that the files can be properly re

Answer 1

The encoding for the File-Entries in ZIP is originally specified as IBM Code Page 437. Many characters used in other languages are impossible to use that way.

The PKWARE-specification refers to the problem and adds a bit. But that is a later addition (from 2007, thanks to Cheeso for clearing that up, see comments). If that bit is set, the filename-entry have to be encoded in UTF-8. This extension is described in 'APPENDIX D - Language Encoding (EFS)', that is at the end of the linked document.

For Java it is a known bug, to get into trouble with non-ASCII-characters. See bug #4244499 and the high number of related bugs.

My colleague used as workaround URL-Encoding for the filenames before storing them into the ZIP and decoding after reading them. If you control both, storing and reading, that may be a workaround.

EDIT: At the bug someone suggests using the ZipOutputStream from Apache Ant as workaround. This implementation allows the specification of an encoding.