Automatic generation of domain objects and database population framework

Question

Hi, I've been working on my own project for a while now, having a good picture of what my business model should be and what domain should back it up I've run across an issue which I guess is very common in the community: What happens with all this objects in the domain?
To test them against a database I've to generate some of them, persist them and then run various operations to see if they work properly. The problem is that generating them and then populating your local database can be tedious at times. So I came up with this idea (maybe not a original one, it never is) to create a tool (a framework maybe) capable of feeding on POJOs inside JARs or some other class resource, creating mappings to generators (which are, of course, generic and use reflection to do their work) and then run all those generators a number of times placing their output into several sets and then persist the objects inside those sets using an EntityManager. All the dependencies must be provided at runtime, the tool does not have to know which are those classes it has to generate instances for.
Generating them through reflection shouldn't be much of a problem if I do it straightforward, the key of the matter is that it cannot be as straightforward as I would like it to be, for every class in the provided JARs I've to match them with configuration properties defined somewhere (XML maybe or Annotations which this object should already have) because not every field on the instance can be initialized the same way, and I don't mean their type either since I can know it through reflection, but many of these objects have database constraints declared, for example, and I've to take that into account when initializing the fields that are constrained.
Also on occasion I would like to have a class generated with data extracted from another source and not hardcoded into the generators (an XLS for example) which can be very practical for my production environment. Taking all of these into consideration I can see how my development time has increased tenfold.
Anyway, my question is simple. Do any of you know an utility or framework which could at least facilitate some of these tasks?

Answer 1

I think the usual way to test items is via JUnit. There are also other test suites based on JUnit such as JSUnit (for javascript testing), cactus, etc.
For testing, I try to test each object in isolation. For testing DAO objects, in each test, I write some test data to the development database (not production database), perform my test, then remove the test data (cleanup). I put the cleanup in a finally block to ensure it always runs (in case an exception is thrown). An alternative is to use mock objects (search google for something like 'java mock objects database junit'). Also in each test, I do the asserts that exercise the object as they would normally work first, followed by abnormal conditions, followed by conditions that may throw exceptions (if you want to test to that degree). You also might want to add code to automatically block the JUnit tests if it detects its running against production instead of development.