dynamic finder method

[smirakr]

Hi,

I'm working with CMP2.0 EntityBean with JBoss3.0 alpha. I have following problem:

I want to specify an user filter (eg. using EJBQL or SQL) on client side, call find method on home interface with this filter and obtain collection of beans.

My question: can I specify dynamic filter on client side? (found nothing in ejb specification 1.1 or 2.0) - If I can not then why? Is any other way how to do that?


Thanks.

[jbossuser]

Not sure what you mean by user filter. Do you mean you want your finder to return limited results based on user input? Or based on the user identity?

[smirakr]

I mean limited results based on user input,

eg. on client side:

String query = "age > 15"; // client generates query dynamicaly

PeopleHome h = ... // obtain home of PeopleEntityBean which has a persistent attribute "age"

Collection beans = h.findByQuery(query);

[jbossuser]

I do something similar to this, but I have developed a reflection framework and utilize a HashMap value object that allows my client side to know what properties are available from a given bean. I couldn't find anything for free in the EJB spec to satisfy this need.

[dsundstrom]

This is on the features list, but is a very low priority. In the mean time, I suggest that you write a BMP style cutom finder. Just declare your finder in the home and then provide an implementation in you bean implementation class. The method is named ejbFind(your args). This is a pain because you have to write some JDBC code, but usually an application only needs a couple of dynamic finders.

[abrasax]

Hi,

I have a similar problem. I also use Hashtable structure for passing flexible parameters to my finder... I've written this finder using JDBC. I create the statement, get some ResultSet and return a collection of primary keys... This works for my BMP beans, but not for CMP2.0 beans. What kind of data is the BMP style finder in a CMP bean expected to return and how can I transform the primary keys into that? Can someone help me?

Best regards and thanks
Martin Stepanek

[abrasax]

Sorry, I found, what was wrong, just a few minutes after posting the yester post. I implemented the custom finder as a home method, ie. ejbHomeFindByAnything, instead of ejbFindByAnything, and so the container didn't transform the returned primary keys into proxies... Now it works fine :o) Mea culpa :o)
Martin

[pazu]

You may also want to look at the new EJB-QL query compiler and the Dynamic-QL feature. Take a look at this thread:

http://main.jboss.org/thread.jsp?forum=46&thread=9743