How hard is it to add a reflection/cglib type alternative to the upfront bytecode generation (like hibernate does) to save us from the development-time pain?
Not particularly hard. There are a few APIs that would break for some cases, but it's even pretty straightforward to do a subclassing approach for property-based access type without losing much performance -- the only cost in that configuration is with persistent-new instances. -Patrick On 5/17/07, James.Strachan <[EMAIL PROTECTED]> wrote:
Firstly before I start, openjpa is a great piece of software; I'm particularly fond of the documentation and in particular the query language parts. The CSS for the site is also awesome :) However compared to hibernate, openjpa is still pretty painful to use from an end users perspective and I don't think this should be the case; plus I don't think it'll take much time to fix. While the pain is still fresh in my mind I thought I'd post on how much more painful openjpa is to use in a project. If you're short on time, the basic idea is its that bytecode post processing stuff thats to blame :). Yes I know its probably faster that way - its just so painful for Java programmers to work with. (And yes I know one day we'll all have IDE plugins that hide the bytecode stuff etc etc). So the first thing is having to mess with your build (ant or maven) to get the post processing properly integrated. Depending on if you have persistent entities in your main or test area this can often trip you up a little (as it did me). I don't know about folks on this list but the whole idea of having to mess with my maven build gives me the jitters :). When you get that far & the maven planets are aligned with openjpa, the next hurdle you hit is how do you run stuff in your IDE. If like me you use IDEA and maven 2, the project gets auto-created by default for all projects you work on. However these don't work when you use openjpa as you hit the dreaded 'cannot function at all as you've not run the up front bytecode post processor you dummy!' type error when trying to run stuff in your IDE. So you then add the maven-generated classes to the front of the classpath in your project. Hooray, after a day or two's work, you can now actually use openjpa in your IDE and your build. YAY! The downside is that now when navigating around your Java code, whenever you navigate into an entity bean, IDEA shows you the bytecode - not the source code as its confused since the bytecode generated stuff is different to the source code it knows about. So now you're faced with a dilemma - choose between navigating nicely around your source code - or being able to actually run/debug your application. I won't even get into the refactoring pain or having to continuously run maven builds while developing code to avoid getting code completion/compile errors etc. (I prefer to keep in my IDE where possible). Compare this whole malarkey with hibernate. You add hibernate to your pom, generate your project and you're good to go. No messing with your project build; no messing with some secret ninja IDE stuff to be able to actually run & debug your code while still being able to actually navigate the source. It just works. Now it might work in a crappy & slow way and openjpa might be way way more efficient and powerful and whatnot - but I'd rather have a cheap car that just works than a ferrari that you can only drive on a tuesday if its sunny, but not too hot and refuses to even start if its wet. FWIW I've just given up using openjpa for development; its just way too painful. (I'm even hacking projects I work on so I use openjpa in the maven build but explicitly switch to hibernate in development mode; yeah its more work but at least I can use my IDE properly again). I'm cool with putting post processing into the build system (though that should really only be an optimisation); but please can we have some inefficient but usable reflection/cglib type approach so folks can easily switch from hibernate to openjpa (and stay there) without pulling out our hair & swearing too much - or sneaking back at the first opportunity to get an easy life? Please don't take this mail the wrong way - I truly want openjpa to be a success, its a great piece of software. Its just a bit too hard to use out of the box right now. I'd truly like it to be trivial to switch from hibernate to openjpa and never have to go back. How hard is it to add a reflection/cglib type alternative to the upfront bytecode generation (like hibernate does) to save us from the development-time pain? -- James ------- http://macstrac.blogspot.com/ -- View this message in context: http://www.nabble.com/the-pain-of-post-processing-bytecode-%28another-beg-for-a-simple-reflection-cglib-alternative-like-hibernate%29-tf3770760.html#a10660986 Sent from the open-jpa-dev mailing list archive at Nabble.com.
-- Patrick Linskey 202 669 5907
