Written by the inventors of the technology, The Java(TM) Language
Specification is the definitive technical reference for the Java(TM)
programming language. If you want to know the premise meaning of the
language's constructs, this is the source for you.

The book provides complete, accurate, and detailed coverage of the syntax
and semantics of the Java programming language. It describes all aspects of
the language, including the semantics of all types, statements, and
expressions, as well as threads and binary compatibility.