AspectJ is a seamless aspect-oriented language
extension to Java(tm). It can be used to cleanly
modularize the crosscutting structure of concerns
such as exception handling, multi-object protocols,
synchronization, performance optimizations, and
resource sharing. When implemented in a
non-aspect-oriented fashion, the code for these concerns
typically becomes spread out across entire programs.
AspectJ controls such code-tangling and makes the
underlying concerns more apparent, making programs
easier to develop and maintain. The project goal
is to support the AspectJ compiler and core tools.