ByteBuffer class was introduced in java 1.4 to ease working on binary data. It's especially suited to use with primitive type data. It allows the creation, but also subsequent manipulation of a
bytes on a higher abstraction level
If you're using SAS to produce reporting of some sort, you're going to find yourself needing to copy a file at some point. I've mostly used this method for copying an excel template, and then dumping data via PROC EXPORT into the new file I've created.
This is a great example I've found from Chris Hemedinger (http://blogs.sas.com/content/sasdummy/2011/06/17/how-to-use-sas-data-step-to-copy-a-file-from-anywhere/).