/**
* Update the central directory signature of a .jar.
*
* @param file the file to process
* @param searchPattern the search patter to use
* @param badSkipBytes the bad bytes skip table
* @param newSig the new signature
* @param endSig the expected signature
* @throws IOException
*/
private static void updateJar(
final File file,
final byte[] searchPattern,
final int[] badSkipBytes,
final int newSig,
final int endSig)
throws IOException {
final RandomAccessFile raf = new RandomAccessFile(file, "rw");
try {
final FileChannel channel = raf.getChannel();
try {
long pos = channel.size() - ENDLEN;
if (!validateEndRecord(file, channel, pos, endSig)) {
pos = scanForEndSig(file, channel, searchPattern, badSkipBytes, endSig);
}
if (pos == -1) {
// Don't fail patching if we cannot validate a valid zip
PatchLogger.ROOT_LOGGER.cannotInvalidateZip(file.getAbsolutePath());
return;
}
// Update the central directory record
channel.position(pos);
final ByteBuffer buffer = ByteBuffer.allocate(4);
buffer.order(ByteOrder.LITTLE_ENDIAN);
buffer.putInt(newSig);
buffer.flip();
while (buffer.hasRemaining()) {
channel.write(buffer);
}
} finally {
safeClose(channel);
}
} finally {
safeClose(raf);
}
}
