[Geotools-devel] DefaultCore and Factory follies

[Ian S. <Ian...@ar...>]

Hi,

While building defaultcore, I found that it fails because the
ToolListImplTest throws a bunch of NullPointerExceptions. This of course
is because an exception was eaten in the ToolFactory. 

Before rehashing my exception spiel, I pondered why it is a factory is
needed for tools. I never reached a conclusive answer. It seems that in
all other gui apis, you pick and choose your implementations. Interfaces
define the protocol and contract between the moving pieces, the user
picks the implementation. The factory approach buys nothing but
confusion here.

In addition, the usage of a non-qualified System property will, given
enough monkeys, some typewriters, and enough time, will be stepped on.
Ex.
System.getProperty("thing") MONKEY PRONE
System.getProperty("foo.bar.baz.thing") MONKEY RESISTANT
-------------------------------------------------------

While mucking around with shapefile, I noticed the anti-pattern usage of
FeatureFactory and FeatureTypeFactory. These classes are in defaultcore.
Because each DataSource uses these classes, they are also tied to
defaultcore. It seems that to be of any use, a factory should reside
with the interfaces it produces implementations of...
So as it is, this prevents client code form providing an implementation
other than FlatFeature (maybe allowing mutability for some custom
application).

Ian