Configuring SpringSource Tool Suite wth AspectJ

How can I configure the SpringSource Tool Suite(ver 2.3.0) Spring project to accept .aj (AspectJ) file?

Currently it does not recognize .aj file.

And I cannot add *.aj file because it's 开发者_如何学Pythona Spring project, not an AspectJ project.

Spring project can be an AspectJ project at the same time.

To configure your project as AspectJ right-click your project in Eclipse, select Configure/Convert To AspectJ project. Additionally you can enable Spring Aspect Tooling by selecting Spring Tools/Enable Spring Aspect Tooling