For Play 1.x projects perform the following steps:
$ cdplay $ play idealize (open the .ipr file with IntelliJ -- remember to explicitly pick up that file).
In Intellijs UI, press "Project Structure" (CTRL+ALT+S)
Set the SDK to the one you want to use. Example /opt/oracle/jrockit1.6.0
Project Settings>Modules, exclude the following folders:
- nbproject
- precompiled
- target
- test-result
- tmp
- war
Alternatively, to ignore folders in a way that survives running play idealize again, you can ignore the files in Settings (Ctrl-Alt-S) -> IDE Settings -> File Types -> Ignore files and folders
add this: ;tmp;precompiled;target;.settings;nbproject;war;.classpath;.project
(To find it, I normally open settings and search for "ignore", then File Types are easy to spot in the short list.)