JAC Milestone 2001

JAC (Java Aspect Components) is a framework for aspect-oriented programming in Java. It is developed as a joint research project between the CEDRIC-CNAM and LIP6 computer science laboratories. This report gives a snapshot of the project as of September 2001. Unlike languages such as AspectJ which are mostly class-based, JAC is object-based and does not require any language extensions to Java. It uses the Javassist class load-time MOP. An aspect program in JAC is a set of aspect objects that can be dynamically deployed and undeployed on top of running application objects. Aspect objects may dene three kinds of aspect methods: wrapping methods (that wrap application methods and provide the ability to run code before and after the wrapped methods), role methods (that add new functionalities to application objects), and exception handlers. The aspects composition issue is handled through a well-dened wrapping controller that species for each wrapped object at wrap-time, runtime or both, the execution order of aspect objects.