This book is like a quick tutorial and introduces the most important parts of Struts. It shows you a door to know Struts but can't help you become an expert. Once you know what struts is. You might need another book, "Struts in Action". "Strus in Action" lists more details, which you will need when developing your struts applications.

Also, after reading the book, I found some errors or unclear issue. Such as:
In Chpater 1, it didn't tell readers that they must copy *.tld files to WEB-INF.
In Chpater 6, it didn't tell readers how to config Locale.

Generally speaking, this book is still good enough for a beginner to buy.