I have my below layout in which I need to represent my data and then finally I need to make one byte array out of that. I need to represent my data in the below format from Java code and then send the byte array to my C++ program which in turns c++ program unpacks the byte array and extract the relevant stuff from it -
// below is my data layout -
//
// key type - 1 byte
// key len - 1 byte
// key (variable size = key_len)
// timestamp (sizeof uint64_t)
// data size (sizeof uint16_t), this is unsigned 16-bit integer.
// data (variable size = data size)
So I started like this in Java which works fine on a simple use case which makes a single byte array out of this but I am thinking my dataSize
calculation is wrong since I am using Short
for the dataSize
which can take maximum value as 32767
but dataSize
specification is uint16_t
as shown above which is unsigned 16-bit integer which can take maximum value more than 32767
.
byte keyType = 101;
byte keyLength = 3;
byte[] key = {27, 55, 111};
long timestamp = System.currentTimeMillis();
byte[] data = "string data".getBytes("UTF-8");
// this is looking wrong to me since dataSize is uint16_t in my C++ specifications as shown above
short dataSize = (short) data.length;
int totalSize = (1 + 1 + keyLength + 8 + 2 + dataSize);
ByteBuffer bytes = ByteBuffer.allocate(totalSize);
bytes.put(keyType);
bytes.put(keyLength);
bytes.put(key);
bytes.putLong(timestamp);
// so this is also wrong
// what is the right way to send the dataSize?
bytes.putShort(dataSize);
bytes.put(data);
// write everthing as a single byte array:
byte[] byteArray = bytes.array();
Let's say if the length of data is 37714
(data.length), then dataSize
will come as negative -27822
.
So my question is - Is there any way I can have unsigned 16 bit Integer in java which I can use in my above code or some way to cast it?
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