Java articles

Primary tabs

Lambda Recipe for attribute validation of Collection of POJOs

So here is a recipe you can use to validate a POJO attribute for some value. In my case I will show you how to check if attributes were set to null. But you can expand on the example as an exercise for yourself.

So here is the template method for a single object and a collection of objects:

Adf :1-1-association returning more than one row fix by overriding findOrCreateAssociationAccessorRS


So this was a strange issue, I face when writing a certain Junit test for a 1:1 association. I was creating a new row which partially fullfilled the 1:1 association condition, and when programmatically asking on this 1:1 assocaition about the other end, the newly created row was getting returned.


ADF DI - How to operate on a selected row in the table component within excel

ADF-DI Excel


ADF DI is ADF's desktop integration that enables a user to work with data in an excel sheet. It is not too feature rich and has its limitations, but it also does well, what it sets out to do. Basically batch creates, deletes and updates are really no problems for tables.


A case of oracle.jbo.TooManyObjectsException : Change createRowFromResultSet to createInstanceFromResultSet


So there are some documented cases of this exception happening and some remedies there-in, if you google this problem.

What if you think you don't fall into this category. So let me "describe" for you a scenario and if you fall into this category, this might save you some pain in troubleshooting this scenario. Again, this might not be the case for you and simple plain vanilla advice might be all you need. If the description some how matches your use case, you can try the solution I propose.

Part 3 : Output Debug SQL statements on a Managed Server on a Production Weblogic 10.3 Cluster

So if you have already read my debugging adventures on a production clone Weblogic server part 1 and part 2, this can be called the part 3 of that series.

Part 2 : Remote Debugging a Managed Server on Production Weblogic 10.3 Cluster via SSH tunnelling

So this is a follow up article to part 1 here. If you are reading this, I am assuming you were not able to connect your debugger to the port opened in part 1, same as me. Well don't despair. There is a solution. In my case apparently only common ports were opened on the system, as it was supposed to be built close to a production system. Or actually some network switch or a physical hardware must be blocking access to the port. For this part, I was not sure. And the IT person supporting me also probably also didn't know the cause.

Importing Sample Maven projects in Eclipse for the book OReilly's Enterprise JavaBeans 3.1

So while reading this book, I though I might as well get the source code and look and run it in an IDE instead of just glance at it in the book. So turned my attention to section V, examples and proceeded to the anonymous git cloning instruction and building as below :

Database Time Interval Based View Criterias in ADF View Objects

So this is more of a cookbook recipe article to show you how you can create time based View Criterias using sql fragments for your ADF ViewObjects.

Important point to note up front. Your database and application server might be running in different time zones. So you need to place attention to this fact when designing your View Objects and View Criterias. For the purpose of this article, I am going to assume that the user is building queries that orient themselves around the database time.

Regex Lookahead and Lookbehind : Match Prefix and Suffix string but only accepting anything in between

Reg ex, lookahead, lookbehind

So there is a little known construct in regex of lookahead and lookbehind, that java regex also supports atleast upwards from java 5. This is exactly what you need if the desired match lives between a known prefix and suffix String. Or depending on if you have a prefix you can use the lookbehind construct and if you have a suffix only, you can use the lookahead construct.

So the lookbehind is represented by (?<=X) and lookahead is represented by (?=X).