Currently this seems to be the only RMI book in print. It is not a badly written book - it has fairly straightforward explanations, examples and case studies. However, I feel that it fails to meet its objectives. It claims to be suitable for intermediate/advanced Java programmers. This is not correct, as it is really an introductory text on RMI. I would like to see a lot more in depth RMI treatment.
The book is divided into four sections. (I) Overview of RMI. This presents an overview of RMI and covers some of the common difficulties faced in network programming. (II) Advanced RMI Concepts. This presents the difficulties faced when transmitting data across a network and how RMI overcomes these using serialisation. (III) Real World Applications of RMI. This presents two separate concrete examples of RMI. The examples are intended to be extensible and appropriate as starting points for ones own implementations. (IV) RMI API Quick Reference. Similar to the javadoc HTML for the RMI package hierarchy.
The main text of the book is a mere 250 pages and this includes a reasonable amount of code. Some of the code is needlessly repeated (portions of a program along with the complete program). There are a few minor problems with the book that could be addressed in the next edition (minor typos, extra diagrams and slightly clearer explanations). Overall, it is a bit pricey for what it offers.