java.util.zip.ZipException: error in opening zip file

Solution 1:

Make sure your jar file is not corrupted. If it's corrupted or not able to unzip, this error will occur.

Solution 2:

I faced the same problem. I had a zip archive which java.util.zip.ZipFile was not able to handle but WinRar unpacked it just fine. I found article on SDN about compressing and decompressing options in Java. I slightly modified one of example codes to produce method which was finally capable of handling the archive. Trick is in using ZipInputStream instead of ZipFile and in sequential reading of zip archive. This method is also capable of handling empty zip archive. I believe you can adjust the method to suit your needs as all zip classes have equivalent subclasses for .jar archives.

public void unzipFileIntoDirectory(File archive, File destinationDir) 
    throws Exception {
    final int BUFFER_SIZE = 1024;
    BufferedOutputStream dest = null;
    FileInputStream fis = new FileInputStream(archive);
    ZipInputStream zis = new ZipInputStream(new BufferedInputStream(fis));
    ZipEntry entry;
    File destFile;
    while ((entry = zis.getNextEntry()) != null) {
        destFile = FilesystemUtils.combineFileNames(destinationDir, entry.getName());
        if (entry.isDirectory()) {
            destFile.mkdirs();
            continue;
        } else {
            int count;
            byte data[] = new byte[BUFFER_SIZE];
            destFile.getParentFile().mkdirs();
            FileOutputStream fos = new FileOutputStream(destFile);
            dest = new BufferedOutputStream(fos, BUFFER_SIZE);
            while ((count = zis.read(data, 0, BUFFER_SIZE)) != -1) {
                dest.write(data, 0, count);
            }
            dest.flush();
            dest.close();
            fos.close();
        }
    }
    zis.close();
    fis.close();
}