JPA embedded sample

During my last talk on Betabeers, titled “Introduction to Java EE”, I was asked if JPA and Bean Validation could be used in stand-alone applications. I had seen some examples of those utilizations, but, to be perfectly honest, I had never used, so I’ve written a small sample that shows how to use JPA and Bean Validation in that context. Please, follow this link to review my source code.


Debugging Java Stored Procedures

I’ve been a fan of developing Java software stored in Oracle Databases for the last years, it’s the perfect partner of PL/SQL,  where this structured language is difficult to deal with or simply can’t achieve the goal.

One of my first problems was remote debugging, a common issue for every programmer.

First of all, I asked my DBA for the DEBUG CONNECT SESSION system privilege. When I got it, I had to configure my JDeveloper project for remote debugging, I started using the version 10g of this powerful IDE, so I changed the project properties in order to listen for JPDA (Java Platform Debugger Architecture) connections:

Project properties for remote debugging, JDeveloper 10g

Nowadays, I’m working with JDeveloper 11g, where I have to configure a Run/Debug/Profile within the project properties, clicking on the Remote Debugging check-box of the Launch Settings and adjusting the same parameters of the former version:

Project properties for remote debugging, JDeveloper 11g

Later on, the next step was to set the breakpoints I needed in the code, so I could go to the menu Run → Debug, in order to listen for remote debugging sessions. At this point, I was asked for the details of the connection:

Listening process parameters

Once I started the listening process, I could check for it checking the Run Manager.

The next step was to run SQL*Plus (nowadays I use SQLDeveloper), logging on the Database and calling the procedure dbms_debug_jdwp.connect_tcp with two VARCHAR2 parameters: the IP direction of my PC and  the port where my IDE was listening for JPDA connections.

After that, I started my debugging session calling the PL/SQL wrapper from SQL*Plus.

When I finished my debugging session, I ran the procedure dbms_debug_jdwp.disconnect from SQL*Plus and I used the Run Manager of JDeveloper to terminate the listening process.

Finally, I would like to talk of some problems I’ve suffered from: sometimes the debugger disconnects the session without any reason, others it disconnects when the Java code throws an exception in order to be managed by the calling PL/SQL, both times the Oracle Database connection is finished too.