This is kind of books PhD academy probably likes the most - lot's of talk, nothing practical.
What authors do is talk endlessly about different security aspects (both general and Java-related)
showing no working code at all (oh, sorry, they do - let me find those 2 pages ..)
I see this book as a bunch of security definitions ( "what is class loader, what is class file
verifier, what is SSL and what is firewall" ) and that's not too much, folks.
Authors even spend time describing some sophisticated security and cryptography packages
developed by IBM (they're naturally IBM-biased in the examples), but whoops - they're
not available for download, IBM internal usage only ! Who cares ..
To summarize, that's an outdated "security for dummies" book, 90% of which are pure theoretical
discussions and it only fits those who see much bigger challenge in writing technical
papers than in developing working code.
P.S.
"Java Security : Hostile Applets, Holes & Antidotes" was written in 1996 and
it's even more dated than this book but I guess I learned more from it.