TopLink

[John Eric Hamacher]

Roland, Kyle and Geoff:

Congratulations on your new book! My question is about TopLink.

TopLink claims to have been around for 10 years, yet I hardly ever hear about it. I have not looked into it, partly because I'm not sure how Oracle's licensing would affect me. Nonetheless, do you offer a look into TopLink in your book? I've never heard anything bad about it . . . is it in some cases a viable alternative to more popular frameworks?

Thanks
Eric

[Mike Keith]

Eric,

I won't speak for Roland et al, and their book coverage, but I can deal with your TopLink questions (TopLink architect is one of the hats I wear at Oracle).

The facts:

- TopLink has been around for over 12 years now (including the TOPLink for Smalltalk days)

- TopLink was just as influential on JPA as Hibernate was, we just didn't go around saying that "JPA was TopLink". Certain people at JBoss claimed that "JPA was Hibernate" and since that time many uninformed people have continued to propagate the myth. (Note: not Mark S and Paul S! They are both way fair and I have been continually impressed with both their correct knowledge and their ability to moderate this forum). See a blog entry on this issue.

- TopLink will continue to be part of the product stack in Oracle, but all of the functionality and source code has been open-sourced into the EclipseLink project. EclipseLink is completely free and open (under EPL)and any interested party can download and use it and/or be a committer on the project

- TopLink Essentials, a scaled down open source version in Glassfish, was the reference implementation for JPA 1.0, and EclipseLink is going to be the reference implementation for JPA 2.0

My opinions:

- TopLink is a deluxe product with an extensive feature set that used to cost a lot of money. Many people found that they could get enough of what they needed in the open source world, which kind of pushed TopLink out of the limelight for a number of years. It has begun to make huge comeback over the last year or two, though, through both the TopLink Essentials and EclipseLink project, which are being used as the default JPA implementations in the Sun Glassfish server, Spring 2.5 and higher, and Oracle's OC4J container.

- I have gone on long enough (maybe too much!) but it suffices to say that I believe the JPA features and extensions to be as good as or better than any other provider on the market (very biased opinion, of course). It has a friendly and helpful user base and lots of developer resources continually adding more features.

If you want info about EclipseLink it can be obtained here.

[Cameron Wallace McKenzie]

It has begun to make huge comeback over the last year or two

I would second that. I'm seeing more TopLink than ever!

-Cameron McKenzie

[Roland Barcia]

I have used TopLink, and it is a capable ORM as well. We discuss TopLink in the 1st chapter, and us choosing not to cover it as a chapter in the template does not mean it is not a good technology.

Anyone can apply the principals in the book with any ORM and there were other technologies that we wished we had time to cover.

[Geoff Hambrick]

Was as much of a space constraint as a time based one.

See my related post for more details.

Ok then, Geoff

[John Eric Hamacher]

Thanks for your responses. I'm glad to hear it is coming back. Sometimes good technologies can be held under water by bigger ones which have a larger following and more documentation.