Topic: Java objects

[ober]

So in my class, I'm pulling all of the records of a certain type out to be displayed in a table.  Each record will have about 4 elements.  What is the best object to store the records in to pass that back to the JSP for display?

[Perspective]

Create a class that represents the object and pass a List of those objects. Like class "Person" or "Sale" or whatever each record represents.

[ober]

Ok, unrelated question... what does it mean when something has a cast of <T>???

[Perspective]

It means that class takes another class as a parameter, just like C++ templates. For example, if I want to make a Map class that maps strings to some arbitrary objects, I could make it be Map<T> and have it map Strings to objects of type T. The benefit is that I can have functions take parameters of type T, or have return type T and not have to constantly down-cast java.lang.Objects. Down-casting can be dangerous and results in run-time errors instead of catching compile time errors. Also, you can have things like Class<T extends OtherClass> and know that whatever class T is, it will extend OtherClass.

[Perspective]

http://en.wikipedia.org/wiki/Generics_in_Java

[ober]

I should have taken at least one more Java class in college.

[charlie]

I don't know if Java generics existed when you were in college.

[ober]

Oh.  Well, regardless, I get hung up on stupid Java shit constantly.  Well, that and the massive amount of java objects in this code base that I don't fully understand.  I know what I need to do, but the simplest things, like reading from the DB are so fucking convoluted. 

[webwhy]

totally agree...raw jdbc is fucking terrible, and i'd imagine that's what you guys are using in an old JSP/Servlet app

[ober]

Well... we are using Oracle's TopLink for cache management, which has it's own set of shit to deal with.  Like you have to create a descriptor of the class you're using and worry about which objects stay in the cache and which don't and a bunch of other things I haven't even figured out yet.

We have other libraries to write direct queries if we need to but I wouldn't say those are any easier.