jMimeMagic is a Java library for determining the MIME type of files or streams, this you can find on google i you search on jMimeMagic, but is this possible without using this jar file from jMimeMagic ???
author and iconoclast
So by "binary bytes" you mean that the bytes represent certain non-text file types? Well, some file types have a magic number -- the first few bytes are always some certain value that identifies the file. For example, the first four bytes of a Java class file are 0xCA 0xFE 0xBA 0xBE , and the first few bytes of a GIF image are 0x47 0x49 0x45. But not all file types have a magic number, which is why figuring out the type of a file from the bytes is sometimes tricky.
The web site Wotsit's Format is a repository of information about file formats: it will likely have all known information about whatever file formats you're interested in.