public static void main(String[] args) throws IOException {
FileInputStream fin = new FileInputStream(args[0]);
GZIPInputStream gzin = new GZIPInputStream(fin);
ReadableByteChannel in = Channels.newChannel(gzin);
WritableByteChannel out = Channels.newChannel(System.out);
ByteBuffer buffer = ByteBuffer.allocate(65536);
while (in.read(buffer) != -1) {
buffer.flip();
out.write(buffer);
buffer.clear();
}
}
/**
* Decode file charset.
*
* @param f File to process.
* @return File charset.
* @throws IOException in case of error.
*/
public static Charset decode(File f) throws IOException {
SortedMap<String, Charset> charsets = Charset.availableCharsets();
String[] firstCharsets = {
Charset.defaultCharset().name(), "US-ASCII", "UTF-8", "UTF-16BE", "UTF-16LE"
};
Collection<Charset> orderedCharsets = U.newLinkedHashSet(charsets.size());
for (String c : firstCharsets)
if (charsets.containsKey(c)) orderedCharsets.add(charsets.get(c));
orderedCharsets.addAll(charsets.values());
try (RandomAccessFile raf = new RandomAccessFile(f, "r")) {
FileChannel ch = raf.getChannel();
ByteBuffer buf = ByteBuffer.allocate(4096);
ch.read(buf);
buf.flip();
for (Charset charset : orderedCharsets) {
CharsetDecoder decoder = charset.newDecoder();
decoder.reset();
try {
decoder.decode(buf);
return charset;
} catch (CharacterCodingException ignored) {
}
}
}
return Charset.defaultCharset();
}
