Don’t release the app module yet!

I was well on my way to a new record in creating and deploying a web-service using Oracle ADF tooling when a bug hit me! No matter what I did the View Object instance within the AM would be null. So for example, I was testing the web-service implementation class as a Java main, creating…More

Oracle Weblogic ADF – Application Module Datasource Connection

For a good idea about JDBC URL vs JDBC Datasource see: Configuring JDBC Datasource According to Oracle “A data source is a vendor-independent encapsulation of a database server connection”. When deploying an Oracle ADF application with a bc4j (Business Configuration) to a stand-alone Weblogic instance, you need to make sure your data-source is configured…More

Oracle SOA 11g Install – RCU Issues

Introduction: During the installation of Oracle SOA Suite 11g, we saw errors related to a DRIVER_INFO error.   Searching on the web revealed that this could be a RCU issue … however attempts to uninstall and reinstall the RCU Schemas caused nothing but more pain (errors related to missing Metadata repository, having to manually configure the…More

Weblogic – where do I put my JDBC Driver lib?

Introduction: We will walk through a quick example of how to resolve “weblogic.common.resourcepool.ResourceSystemException: Cannot load driver class:” errors and learn where to install the JDBC driver libraries to fix runtime issues. Background: I was playing with ADF samples and had a database connection to a MySQL instance. This was achieved by adding the MySQL-Connector library…More

Creating Root Application Module Instance – Oracle ADF

Introduction: When developing ADF Business Components, we might need a handle to an Application Module (AM) instance. I have used the AM instance in the past to a) invoke the methods on the Application Module for testing – think quick and dirty Java main for validating configuration is okay or for debugging through the method…More

SQL Developer – Date Format

You are on SQL Developer and have a date-time column, you run a query and it only displays the date. You could do a “to_char(mydatefield,’MM/DD/YYYY hh24:mi:ss’) ” but then you will have to do it for ALL date fields and change all your saved queries. You wish there was something in SQL-Developer that would apply…More

Java Maps – Complex Key Example

…so someone asked me today about Java Maps, Oracle Coherence and using complex keys i.e. non-string keys.   The easy part is in declaring your Collection object and storing the value using the complex key object. The tricky part is when you need to get the value back from the map using the complex key. You…More

Using Range Paging in ADF – an example

Introduction: We recently had a requirement for loading large chunks on data from Oracle table into a background process using Java and ADF framework.  We were not allowed to use “straight” SQL and had to stick to ADF framework!  It took a little bit of time to understand how range paging worked – you see,…More

JDeveloper memory settings

Did you just get the “JDev is low on memory” error? or you have a beast of an application where you are trying to initialize a tree with a million or so nodes? (I was!) So .. first thought is, its gotta be some “config” file (because I did not start JDev as a jar…More

Boggle Solver

Attempt 1: Use Arrays and Lists and a recursive function to loop over all letters in the boggle board and find all possible words of size [min-length] to size [max-length] where min-length >= max-length. Code: Apr 16, 2010 2:42:59 PM 1 package boggle; 2 3 import java.util.ArrayList; 4 import java.util.Arrays; 5 import java.util.HashSet; 6 import…More

Why do OJC and Javac differ?

Introduction: A certain developer wanted to specify Generic Type in his abstract Java class, like the Java Map interface and AbstractMap class, in the manner described in Code Sample A, below. Setup: – We have 2 environments desktop and remote hosts – Applications are built on the desktop in JDEV (11gR1) using OJC by default…More

Python + MySQL in Ubuntu (9.10)

Assuming you did a fresh install of Karmic Koala – Ubuntu 9.10 Here are the steps: – Install Python: apt-get install python2.6 – Install XAMPP/LAMP stack: sudo tasksel install lamp-server After you install follow the steps on setting up the root password see the notes here . – Install MySQLdb: I tried downloading the sourceforge…More

Stuff to read

Must read up more on these – download, test, play JGraph – Parallel port interfacing made easy – Wireless Rabbit Web Server – Introduction to WI-FI, Wireless LAN basics, Wireless Security, Rabbit Wireless doc – Introduction to ZigBee – I Make Projects – Wireless Detector  (Hooking up a vibe motor…More

Design Patterns

Okay so I am officially going to start working through each and every design pattern in the “Sun Certified Enterprise Architect for J2EE Technology” study guide. I keep going through the book from time to time and while it is fun reading UML, there is absolutely no replacement for code and your own experience. I…More

Matrix manipulation

When solving Boggle, Sudoku or some n-by-n board game or when doing Image analysis or Parallel Computing – it is often useful to be able to represent one-dimensional data structures in 2-dimension and vice-versa. Simple formulae exists for doing this conversion, as illustrated below: Converting from Row by Col 2-dimensional (2-index) format to a 1-by-(Row*Col)…More