Background: 

When you work with J2EE applications, you usually 
have to work with several XML configuration files 
(for the frameworks that you work with). If you 
work inside a firewall, you need to register and 
use a local copy of the DTD or XSD in order to get 
validation and code completion of the XML file. It 
is important to understand that practically all 
developers who work on a real J2EE application 
rely on some kind of technology that involves a 
config file: web services, portlets, use JSF, 
Struts, Tiles... 

It is currently *very* cumbersome to create and 
register such files, and the naming conventions 
are obscure. Here is what you have to do: 

1) Mount a new (dummy) directory in the file 
systems explorer
2) Create an XML catalog file
3) Manually edit the file to match the name of the 
document with the location of the file on disk. 
(You have to understand the role of the name of 
the document)
4) Unmount the dummy directory
5) Switch to the runtime tab and mount the catalog 
file there. 

It would be much easier to do this if I simply 
added a catalog file and edited it (through a UI, 
which can create entries based on parsing the DTDs 
and XSD files. There is no reason why the creation 
and registration cannot happen in one place. And 
it's not obvious that the runtime tab is a good 
place for this since it's more something that the 
text editor uses. (I originally looked for this 
functionality under the Options tab). 

Suggested UI: 

First of all, I don't think it's a good idea to 
use the term "XML Entity Catalog" in the primary 
user interface, this does not help novice users 
such as myself. 

I think most users expect to find this 
functionality in the same place where they 
configure other editor options, so the Options tab 
would be the obvious location. If you plan to 
introduce another obvious location for configuring 
the editor, that should do too. 

You may wish to implement the functionality using 
XML Entity Catalogs in the background, but there 
is no reason to expose this term to users. All the 
user wants to do is to ensure that the IDE knows 
that a particular file is available locally, so 
the UI should just be based on browsing for the 
file. 
 
If that's not possible, it should at least be 
possible to create those catalog files from the 
XML Catalogs node in the Runtime interface, but 
that's already a stretch. If that case, the 
catalogs should have UI to add new catalog 
entries.