Monday, November 25, 2013

Problems with Persistence (begging)

I am still struggling with the OSGi persistence story. I am therefore doing some research on OSGi and persistence and I still find the whole Java persistence story quite confusing and complex. Part of my problem is that I see lots of frameworks but it is quite hard to see code that really uses those frameworks. Virtually all tutorials and examples look highly contrived and seem to ignore issues like caching, security and look rather lax with transactions.  

I wonder if people reading this blog could share with me a typical production source or class file showing:
  • How entities are defined
  • The persistent use of the entity, i.e. the part where the SQL will be generated. I.e. places where the PersistenceManager, EntityManager, SQL generation is used
  • How results are cached

A single source or class file per issue is best. Adding a small description how you use persistence (Aries, JPA, JDO, JDBC, etc), the primary issues you face, and describe your environment is highly appreciated. 

I know from my own experience that there is often a feeling that your own code is not up for showing to others but please send me the raw unadulterated code; I need to see how it is today, not how you think it should be. Obviously I am not interested in what the code does or where it is used so feel free to remove comments (if any!) and change names (or just send class files). I am just looking for a couple of hundred of real world samples to extract the patterns that are actually popular in our industry. Obviously I will not share that code with anyone and treat it fully confidential. 

So in this case, do not ask what the OSGi can do for you, but for once, ask what you can do for the OSGi! ;-)

Please? Come on, it only takes 3 minutes. Send your 4 files to: Thanks!

If I get some interesting result I promise share the conclusions with you in this blog. Deal?

Peter Kriens @pkriens


  1. Hi Peter,

    Are you only looking for examples of SQL based persistence or also Mongo etc?
    Besides that, are you just looking for examples within OSGi or also Java EE for example ?

  2. Mainly interested in real world persistence. I.e. applications with lots of attributes. Mongo or other models are fine.