Java checksum data inputstream / data outputstream

Hi All
I am looking for a java package that will help me in checking a stream of data.
This will be used on the network and will probably do the checking on the fly.
So the sender will probably send a checksum followed by a delimiter followed by the stream of bytes.
The receiver will store the checksum read the bytes, compute the checksum and compare it with the sent checksum.
Is this how byte streaming checksums are supposed to be done?
Any feedback would be appreciated.