Java Utililty Methods ByteBuffer to Long

int result = 0;
result += readUInt8(b) << 8;
result += readUInt8(b);
return result;

return (bb.getShort() & 0xffff);

int result = 0;
result += byte2int(bb.get());
result += byte2int(bb.get()) << 8;
return result;

if ((buf.position() + length) <= buf.limit() && length <= 4) {
    long r = 0;
    for (int i = 0; i < length; i++) {
        r |= (((long) (buf.get() & 0xff)) << (i << 3));
    return r;
return 0;
...

byte[] data = new byte[8];
bb.get(data);
long l1 = (((long) data[0] & 0xff) << 0) | (((long) data[1] & 0xff) << 8) | (((long) data[2] & 0xff) << 16)
        | (((long) data[3] & 0xff) << 24);
long l2 = (((long) data[4] & 0xff) << 0) | (((long) data[5] & 0xff) << 8) | (((long) data[6] & 0xff) << 16)
        | (((long) data[7] & 0xff) << 24);
return BigInteger.valueOf((l1 << 0) | (l2 << 32));

long result = 0;
result += readUInt32(byteBuffer) << 32;
if (result < 0) {
    throw new RuntimeException(
            "I don't know how to deal with UInt64! long is not sufficient and I don't want to use BigInt");
result += readUInt32(byteBuffer);
return result;
...

return bb.get();

long x = buff.get();
if (x >= 0) {
    return x;
x &= 0x7f;
for (int s = 7; s < 64; s += 7) {
    long b = buff.get();
    x |= (b & 0x7f) << s;
...

long value = 0L;
int i = 0;
long b;
while (((b = buffer.get()) & 0x80) != 0) {
    value |= (b & 0x7f) << i;
    i += 7;
    if (i > 63)
        throw illegalVarlongException(value);
...

return toByteBuffer(buffer, Long.BYTES).getLong();