Dive into Oracle ADF

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 Dive into Oracle ADF   Click to see the XML version of this web page.   (Updated: 2/3/2008; 9:13:47 PM.)
Tips and tricks from Steve Muench on Oracle ADF Framework and JDeveloper IDE

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Monday, July 05, 2004

Markus writes in to ask, "How does the UniquePKValidationBean validation rule that's used on the Account entity in the ADF Toy Store work? There isn't anything in the online help about it."

Firstly, he's right: not in the docs. I filed bug 3745726 to get the documentation on this beefed up in a future release. I also checked the ./BC4J/src/bc4jaddinsrc.zip file that we ship with JDev/ADF and it's not included in there along with the source code for the other built-in validators that we do provide.

So, in the interim, here's the scoop. The UniquePKValidationBean is implemented by a standard BC4J validation rule named JboUniqueKeyValidator that is defined as an inner class in EntityDefImpl. I assume it was defined this way for a Java member-visibility reason, but I don't know the exact history off the top of my head. (Today's a public holiday in the US so I'll have to get back to you on that!) This validation bean gets added when the entity definition object is loaded and the <UniquePKValidationBean/> element is found among the entity object's XML metadata. The runtime implementation simply calls the addUniquePKValidation() method in EntityDefImpl that does the work of adding the validator.

In earlier versions of BC4J, you had to add this validation rule yourself programmatically by overriding the createDef() method of the EntityDefImpl class in a custom Entity Defintion, and manually call the addUniquePKValidation() method yourself. In 9.0.3 we added the design-time support to perform this step declaratively instead of having to write code to do it.


4:57:07 PM    



Andrej Koelewijn dropped me a quick email to let me know that the JSTL Quick Reference that I link to in my ADF Data Binding Primer and ADF Toy Store whitepapers has moved to a new link.

It's "Appendix A" in the sample chapters for the Bayern book on JSTL. I'll fix the original as soon as I can...


3:47:35 PM    


If you are building BC4J/JClient or ADF/JClient applications and deploy in a three-tier architecture, where your thin UI panels run on the client machine talking over RMI-IIOP to the Application Module deployed as an EJB Session Bean, network round trips and their related latency can be a real drag on the responsiveness of your user interface.

My BC4J/JClient Performance Study paper helps explain how to avoid many of the common mistakes that can cause your 3-tier BC4J applications to be more "chatty" than necessary, however over on the JDeveloper OTN Discussion Forum users are discussing a TCP-socket-level protocol acknowledgement whose disabling brings a huge performance gain to three-tier JClient applications. Presumably, the speedup would benefit any three-tier app using EJB over ORMI, not just 3-tier JClient applications. From one of the thread's postings...

The time it took to open one window has been reduced from 20,000 ms to about 1,000 ms. First we tried to set the delay to 0 on the server, and the time reduced to about 1/2 of what we started with. Then we set the delay to 0 on the client machine, and the time reduced to about 1/20 of what we started with.

I'm in the process of confirming how to get the OC4J patch which fixes the issue in Oracle code for you, but for Windows platforms there is a workaround mentioned in the thread that some users are using in the meantime...


3:17:25 PM    


Back from vacation and ready to roll again. I look forward to catching up with the rest of the JDev team to see how our Java One demos were received by developers. I had a chance to watch Thomas Kurian's keynote on sun.feedroom.com to see the JDeveloper and ADF demo. Everything went without a hitch!

Seems like folks have been able to get started with the ADF Toy Store Demo in my absence without any issues, so that is nice to see...

One odd issue came up under Windows 2000 where a customer needed to first run the TestJDBCConnections servlet mentioned in Appendix 2 before the demo would work for him, but otherwise no other surprises have yet been reported.


1:07:32 AM    


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