Have Your Cake and Eat It Too: Meta-Programming Techniques for Java

Ever been envious of how easily Python, Ruby and even JavaScript can “meta-program”? Meta-programming provides new ways of writing your code that goes beyond traditional object-oriented composition or inheritance. It’s like magic: seemingly simple or innocuous code takes over big responsibilities; new methods appear out of thin air. Your code, your primary code, stays simple and easy to follow.

Now, we know you can do that for scripting languages, but what do we do about Java? With the proper context (some kind of framework responsible for instantiating classes), it is possible to emulate many of those same capabilities, by applying a simple set of code transformations at runtime. In this session you’ll learn about meta-programming and how it can apply to traditional Java. You’ll learn about the techniques needed to transform classes at runtime, adding new behaviors and addressing cross-cutting concerns. The presentation will discuss a new framework, plastic, designed for this specific purpose, but also draw examples from the Apache Tapestry web framework, which itself is rich in meta-programming constructs.