Re: Loading Classes from Tables

Walden H. Leverich wrote:
> No, actually I do want to store the class. 

But the class contains no data ... just code.

> Let's say we implement the
> document generator with the ability to ask TextBox, Date and TextArea
> questions. Then we want to add the ability to ask DropDownList
> questions. We'd create a class that knew how to draw the HTML for Drop
> Down Lists and add it into the system and we'd be all set.

So you change your application to handle the new functionality and
re-deploy it.  If you store the code in a blob, and the interface to
that class changes, then your application is broken.

Loading classes from the classpath dynamically is (relatively trivial)
... so if it's dynamic loading you're looking for, check out the various
classloader options.

> I'm really looking for a way to store classes in the DB. Think of them
> as plug-ins. You can develop plug-ins for this system and upload them to
> the system. I want to store the plug-in in a database, but the plug-in
> is a java class.

Yeah, I see where you're going ... but IMHO (obviously) this is not a
prudent way to approach this problem.  I would put the plug-in's in the
jar and just redeploy the jar when you need to make a change.

Mind you, I'm by no means an expert in this area ... so everything I've
said could be total bunk.  :)

david