How do I obtain the number of bytes before allocating the byte size of the array 'handsize' as shown below as the incoming ByteArray data are sent in 3 different sizes. Thanks.

BufferedInputStream bais = new  

BufferedInputStream(requestSocket.getInputStream()); 

DataInputStream datainput = new DataInputStream(bais); 

//need to read the number of bytes here before proceeding.

byte[] handsize = new byte[bytesize];  

datainput.readFully(handsize);