Utils.java

static byte[] readFully(InputStream in) throws IOException {
    // We don't know the final size, and we will only ever iterate over this list
    LinkedList<Byte> bytes = new LinkedList<Byte>();
    // 16kb sounds about right, idk
    final int SIZE = 16 * 1024;
    byte[] b = new byte[SIZE];

    int read = in.read(b);
    while (read == SIZE) {
        for (byte a : b) {
            bytes.add(a);
        }
        read = in.read(b);
    }

    // Finish copying the final bytes in, if there are any left
    if (read != -1) {
        for (int i = 0; i < read; i++) {
            bytes.add(b[i]);
        }
    }

    final byte[] finalArray = new byte[bytes.size()];
    int i = 0;
    for (byte aByte : bytes) {
        finalArray[i++] = aByte;
    }

    return finalArray;
}