Do you think JPA will achieve what JDO could not?

Hi,
I wonder why did Sun need yet another specification while JDO at hand?
JDO did not gain widespread acceptance,do you think JPA will? and if so why?

what makes JPA a better way than JDO,I only came up with 2 ideas

-JPA is new

and Java community likes new tech [but JDO was new once upon a time...]
-JPA spec is subpart of EJB and EJB has acceptence in java developer and vendor camps.

what do you think?

JPA is being widely used, and with Hibernate as a persistence provider, and the depth with which JPA is anchored in the EJB3 spec, I think it has legs. JPA 2.0 looks great as well.

It has a future. It's as strong a bet as anything else out there, if not a bit stronger.

-Cameron McKenzie

This was a long war in the past years. The JPA won, as a consequence that becomes standard in EJB3.
I don't want to start a flame on that, there are a lot of differences between them.

My conclusion on why JPA won are:
- JPA is much simpler than JDO
- JDO can to persist in any type of repository, JPA only in relational databases, BUT the relational databases are the most frequent cases so it is a calculated compromise
- JPA uses annotations a lot (now DTO uses at well, but in war time that was not the case)
- JPA covers the topics of object mapping which are very clear conceptually, JDO has still a lot of functionalities which are not very flexible or too specific
- JPA had at that time support of the biggest software vendors of persistence layers and RDBMS like: Oracle (TopLink, OracleDB) and RedHat (Hibernate)

Thank you Aurelian for this clearly stated answer.

I agree the items

1.JPA covers the topics of object mapping which are very clear conceptually, JDO has still a lot of functionalities which are not very flexible or too specific
2.JPA is much simpler than JDO
3.Hibernate support is big plus [i have doubts on toplinks contribution]

have contributed alot in this victory [since it was a war i thought victory would be a convinient word here

]

and maybe

- JPA uses annotations a lot [after all Hibernate was very popular while only-XML config based so i have doubts on this]

I wish a seperate book on JPA is published.This absence creates a feeling that JPA is not a topic of interest/importance.

As far as I can see the JPA topic is covered in EJB/Hibernate books but a dedicated JPA book is missing.
A book titled Pro JPA is coming as far as I can see from amazon.

In terms of books on JPA there are several:

http://www.amazon.com/gp/product/1590596455/102-2412923-9620152?v=glance&n=283155

http://www.amazon.com/Enterprise-JavaBeans-3-0-Bill-Burke/dp/059600978X/ref=pd_bxgy_b_img_b

http://www.amazon.com/EJB-3-Action-Debu-Panda/dp/1933988347/ref=pd_bxgy_b_img_c

http://www.amazon.com/Java-Persistence-Hibernate-Christian-Bauer/dp/1932394885/ref=pd_bxgy_b_text_b

Wikibooks
http://en.wikibooks.org/wiki/Java_Persistence

yes i know them and already read two of them,

I wish a seperate book on JPA is published.This absence creates a feeling that JPA is not a topic of interest/importance.

my emphasis was on a 'separate' book like http://www.amazon.com/Pro-JPA-Mastering-trade-Persistence/dp/1430219564/ref=sr_1_1?ie=UTF8&s=books&qid=1247755861&sr=8-1

yes, JPA is a subpart of EJB spec but it is not bound and limited to EJBs and as you already know can be used even in j2se.

thanks anyway.