A question for authors Does the book cover earlier Atom standards and make an explanation of the differences, pros and cons over RSS standards and the Atom standard? Are there numerous of examples that one can easily learn from in the book ?
The book covers Atom format 1.0 and Atom protocol (which is still in development).
The book does not cover Atom 0.3, which was not a standard and came with a warning that said "DO NOT implement it or ship products conforming to it," but the ROME parser (http://rome.dev.java.net), which gets a whole chapter in the book, does support Atom 0.3.
2) And make an explanation of the differences, pros and cons over RSS standards and the Atom standard?
3) Are there numerous of examples that one can easily learn from in the book ?
Absolutely. There are numerous simple examples of parsing, generating and serving feeds, plus Part II is a collection of complete applications (podcast server, podcast fetcher, planet generation, blogging chat-bot etc.). You can get all of those applications at http://blogapps.dev.java.net and you can build the separately -- they're all designed to be standalone applications (and all open source under Apache license).