How to parse byte[] (including BCD coded values) to Object in Java

Question

I'd like to know if there is a simple way to "cast" a byte array containing a data-structure of a known layout to an Object. The byte[] consists of BCD packed values, 1 or 2-byte integer values and character values. I'm obtaining the byte[] via reading a file with a FileInputStream.

People who've worked on IBM-Mainframe systems will know what I mean right away - the problem is I have to do the same in Java.

Any suggestions welcome.