java使用Deflater无法压缩图片

Question

java使用Deflater无法压缩图片

public byte[] compress(byte[] data) throws IOException {
ByteArrayOutputStream bos = new ByteArrayOutputStream();
Deflater compressor = new Deflater(8);
try {
compressor.setInput(data);
compressor.finish();
final byte[] buf = new byte[1024];
while (!compressor.finished()) {
int count = compressor.deflate(buf);
bos.write(buf, 0, count);
}
} finally {
compressor.end();
}

    return bos.toByteArray();
}

压缩出来的图片和原有图片大小一致