Hibernate's implementation of JPA has some quirks, such as not being able to handle the eager fetching of two @OneToMany relationships in a single entity without the use of some work-arounds. Although this article is not about these work-arounds I will give a quick overview of the problem and solution to that problem first, before looking at the specifics of the case where I got the error on a entity with two @ManyToOne.

This is part 2 of the Tapestry screencast which is based on the presentation I gave at the first Ferndale Java User Group meeting.

This is my first attempt at a screencast so I am sure there is room for improvement. Please contact me if you have any suggestions.

Saturday, was the 1 st September,the first official day of spring. Besides being a Saturday for a change the day was gloriously warm and sunny. Everything that spring day should be. I spent most of the morning outdoors, walking the dogs, enjoying the warmth and planning my first screencast.

We use hibernate on our projects for the ORM technology. We are starting to use EJB3 now for all new development. Luckily its very similar to hibernate so we don't have to re-skill too much.

Hibernate HQL Inner Join

An issue that I came across recently was hibernate's HQL language inability to handle "inner join on" clauses. If your domain entity model has relationships defined between the related objects then something like

The other day I suddenly started getting this error when running maven 2 on my gentoo box.

Exception in thread "main" java.lang.NoClassDefFoundError: org/codehaus/classworlds/Launcher

Don't you hate it when you figure out a bug only to forget it two weeks later? This usually happens with those bugs which aren't your fault. One such bug I came across recently, was when I was using XFire 1.2.6 and Spring 2.0.2.

When trying to view the wsdl for the service I got the following error in the tomcat logs:

Struts Validations Framework How to

The struts validation framework is quiet straight forward to use but there are lots of little gotchas that slow down the learning process. It should take one no more than two hours to understand and use the validation framework. Here are some of pointers that help new users of the framework.

Its been a busy last couple of days for us here at Jumping Bean! During the short time since my last blog I have had to upgraded my laptop to use Ubuntu 6.06, had to upgrade some desktops to Suse10.1 and one server to Fedora core 5. All I can say is that I am very impressed with this round of distro releases. They are polished and very slick!

A while ago I was researching open source business intelligence applications and came across some real gems that I thought I should share with others. The two big projects I found are Openi and Pentaho. Pentaho is an Eclipse based product and gives developers a complete platform for BI application development based on open source and Java.

Jumping Bean has java expertise in the Java enterprise development and the Java mobile space. Our team of skilled developers can either compliment your existing team or you can outsource the entire development to us.