It was with a heavy heart that I made the decision not to participate in writing Pro Spring 2.5. I am deeply thankful that Jan was around to pick up this book and run with it. Pro Spring has been a big part of my life for over three years, and I didn't relinquish the reins lightly. When Juergen and I set out working on Spring Framework 2.0, I knew that I wouldn't have the time to participate in the writing process and write the software at the same time. Fortunately, Jan was there to step into the breach.

Jan and Apress had additionally planned to release Pro Spring 2.0, but Juergen and I inadvertently made it impossible for them to keep up by making many changes to the Spring Framework. I vividly remember cringing when updating all the JSP form tags, knowing that I was creating yet more work for Jan.

With the 2.5 release just on the horizon, Jan made the sensible choice to forego a 2.0 edition and head straight for 2.5. This was a wise move. The Spring Framework 2.5 release reflects the state of the art in both the Spring Framework and in enterprise Java frameworks as a whole. A guide book to this critical tool is necessary reading for any conscientious Java developer.

I recall, back in the early days of running Cake Solutions, when we decided we needed to hire another programmer. We were very inexperienced at hiring in general, and hiring programmers is fraught with problems. We knew that we wanted to get a graduate, but we never imagined that we would get someone as accomplished as Jan.

I remember, in his first week, he wrote a complete desktop mailing package from scratch—and it worked. Over the last five years, Jan has been at the center of most of the projects run at Cake, many of which are large-scale Java products based on the Spring Framework. His knowledge of Spring comes from an immense amount of practical experience: he has been in the trenches with Spring since version 1.0 and has delivered successful systems on top of it.

To his credit, Jan realized that writing Pro Spring 2.5 was too big a job for just one man, so he roped in the rest of the Cake Solutions team to help him. This prospect excited me greatly— a team of real programmers, with real experience in Spring, passing along that knowledge. There is no doubt that many will find this book to be an indispensable reference.

And so, although I am disappointed at being unable to work on this book myself, I am glad that Jan was there to deliver what so many people have been asking for, an updated version of Pro Spring. Enjoy, Rob Harrop

Principal Software Engineer and Lead Engineer of the SpringSource Application Platform