Open Source vs. Commercial Software

Today I stumbled upon the following article about Open Source vs Commercial Software. It's quite entertaining and shows may of the pros and cons for both open source and commercial software licensing.

http://www.isitedesign.com/insight/08_07/open-source-versus-commercial-web-software.cfm

Enjoy!

Replacing TopLink Essentials with OpenJPA as my persistence provider

During the development of my latest pet project I decided to go head-on with many of the latest Java Enterprise APIs. One of these was the Java Persistence API (JPA), which I had already used in a handful of projects before. On previous projects the persistence requirements were very simple. I could use JPA out-of-the-box with TopLink Essentials which is the standard set-up for a JPA project in NetBeans/GlassFish. However, for this new pet project of mine I was in need of storing large binary objects (BLOBs). I was shocked to discover that TopLink Essentials doesn't support the Fetching configuration for relationships and properties. Instead it will Fetch.EAGER everything in a relationship and property. This made my application crash hard (OutOfMemoryException) when ever I would query for all entities containing the BLOB. So, I set out to replace the persistence provider. First I looked at Hibernate. I used Hibernate before JPA was released and never had much trouble with it. Unfortunately I found that Hibernate also doesn't support the fetching configuration (in JPA mode). That lead me to OpenJPA which really surprised me. It is well documented, clean, easy to use, and support the fetch configuration. I've now replaced the persistence provider on two projects with OpenJPA and the performance has increased significantly. However, here are a few gotchas that you have to look out for:

• Auto-generated identity fields must not have a preset value in your JavaBean (hence, this would give you problems:
  
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id = 0L

  
  Instead you should write
  
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

  


• Collections are Fetch.LAZY by default, so if you got an existing using TopLink Essentials, you have to double check that your relations are not throwing LazyInitializationException upon fetching outside the transation.
  


• Remember to specify the Fetch depth (openjpa.MaxFetchDepth) in persistence.xml for using the Fetch.EAGER configuration


• TopLink Essentials compiles named queries when your application is deploy on the application server, OpenJPA on the other hand compiles the named queries upon first usage.


• When enabling SQL DDL on OpenJPA it doesn't generate foreign key constraints, unlike TopLink Essentials

That's all for now. I'd love to hear about your experiences with OpenJPA or any other persistence provide you find suitable for your need.

Cycling

For the past week I've been cycling to and from work. That might not sound like a big deal to you, but it has certainly been a challenge for me. In the past it has been all to easy to jump into the car and head off for work. No more, I've decided. The distance to work is very do-able, 5.5 KM each way. It's better for me and it's better for the environment. The biggest problem so far has been the uphill route on my way back. Nevertheless, I've made great progress already. The first day was absolutely hell! When I got to work I could barely breathe and I had to spend several minutes in the bike shed to compose myself. On the third day I managed to cut off 5 minutes from the ride, and today I was only plagued by fatigue in my joints. I'm looking forward to seeing how I'll be feeling on Monday and if I can take another week.

MyFaces and Facelets - The Definitive Guide

For the past five months or so, I've had the pleasure of participating as a contributing author and editor of the recently released Apress publication, "MyFaces and Facelets - The Definitive Guide".



It was a great experience that I hope that I'll be able to relive in the near future on other book writing projects. What I liked about the book was the focus on the array of JSF components under the MyFaces Apache project. Most people seem to think that MyFaces is simply an implementation of the JavaServer Faces specification. MyFaces is an umbrella project for JavaServer Faces related technologies. The most famous of the sub-projects is the Tomahawk components project which provides a lot of useful JSF component that I certainly couldn't live without.

The focus of the book is on technologies under the Apache MyFaces project as well as the Facelets technology. Facelets is another very important JSF technology that deserves more attention from the community. There are lots of people using Facelets, but little development is going on to make it truly professional.

The book is not for newcomers to JSF, but for programmers already familiar with the basics of JSF. If you are looking to get familiar with JSF I can highly recommend JSF In Action by Kito D. Mann published by Manning.

Thanks to Zubin Wadia and Hazem Saleh for making the project a great experience!