Java Power Tools by John Ferguson Smart
Java Power Tools provides a fairly detailed introduction to a number of tools for Java programmers. It fits nicely between the O'Reilly Hacks series and having a dozen books like Ant: The Definitive Guide, 2nd Edition. Like the Hacks books, Java Power Tools provides an introduction to a bunch of tools. The Hacks books are great for answering the question "I've heard of that tool, but where does it fit?" But whereas the Hacks books provide just an appetizer, this book provides a main course, enough to get seriously started with the tool being discussed. And then, if you want all the gory details, a Definitive Guide could provide the full five-course meal.
The selection of tools presented was really good, at least for me. For example, I know about continuous integrations servers, but I haven't set one up. At one client site, they were using Hudson, which I had some exposure to, but didn't know much about the others like Cruise Control, Continuum, and LuntBuild. Similarly, I've been using JUnit 3.x for years, but I didn't really know what was different in JUnit 4 or how that compares to TestNG. This book provided me with a great overview of these and other tools. Java Power Tools provides a great way to get up to speed with a general area of tooling (e.g., continuous integration servers) or a good cross-section of the majority of the Java tools in use today.
If I had to pick something to complain about, it would be Part II - Version Control Tools. These aren't really Java tools, although every programmer (Java or otherwise) should be using them. Or given the decision to include version control tools, I'd suggest excluding CVS because it's old and including at least one distributed version control tool like Mercurial (used by the Open JDK project and NetBeans) or git (used by the Linux kernel).
So, in conclusion, unless you have no free will about tool selection or you already know all of these tools backwards and forwards, I highly recommend this book to almost any Java programmer.