We present a system capable of recommending music playlists that take into account the temporal context of the user, i.e. they select user preferences as learned for the concrete time situation of the request.

again. More time is spent covering immutability, and there the concept of the book begins to show through, with good, well-structured arguments as to why immutability is a good idea in Java: controlling the scope of mutation and making object-oriented programming easier and more reliable.In summary: the concept for the book is good, but the realisation of the concept does not live up to the billing. The book is not terrible, but it feels worse for having missed a golden opportunity to explain how to use functional programming concepts in practical settings in a very popular object-oriented programming language. A greatly revamped second edition would be very welcome, if it could find the right level of abstraction at which to transfer the functional concepts into Java -backed by longer and more practical examples.