Manning - Java Reflection In Action

We wrote this book because reflection inspires us. It produces solutions so elegant that they elicit the same sense of wonderment that we often felt as children. It is this inspiration that has driven both of us in our study and practice of reflective programming over the last ten years.

In the early 1990s, Ira Forman was a member of the development team for IBM’s SOMobjects Toolkit, generally known as SOM. It was not a programming language. Rather, SOM was an API to a highly capable and reflective object model. For the second release of SOM in 1994, Ira and Scott Danforth wrote the Metaclass Framework, which used the reflective facilities of SOM to provide useful tools for the rest of the development team and the IBM customers. This may well be the first commercial instance of what has become known as Aspect-Oriented Programming.

Included in the Metaclass Framework was a tool to dynamically create proxy classes. Another tool could wrap the methods of a class with code to execute before and after every method execution (this was the way the trace facility was created without modifying the SOM kernel). Yet another modified a class to be a singleton. In addition, there was a metaclass to support the conversion of plain-old classes into replicated classes (in the context of the SOM Replication Framework, which was programmed by Hari Madduri and Ira). These experiences convinced Ira that reflective programming is cool.