private byte[] loadClassData(JarFile jarFile, JarEntry jarEntry) throws IOException {
        long size = jarEntry.getSize();
        if (size == -1 || size == 0) {
            return null;
        }
        byte[] data = new byte[(int) size];
        InputStream is = jarFile.getInputStream(jarEntry);
        try {
            is.read(data);
        } finally {
            try {
                is.close();
            } catch (Exception e) {
                LOG.error(e.getMessage());
            }
        }
        return data;
    }