Two Fantastic Uses for AspectJ: Part Two, Bridging

NOTE: I’m cross-posting this article on both my Build Chimp and Sonatype blogs. I mentioned recently in part one that using AspectJ to support backward compatibility for Maven is proving a great way to keep the main API free of the clutter associated with supporting old method signatures and classpath structures (for instance, making sure plexus-utils is always available, as it once was from Maven’s core). Today, I’d like to shed a little light on some other aspecting work I’ve done that bridges two previously unconnected manager components inside the Plexus container, to support active component collections. Active component collections are maps, lists, etc. of Plexus components which can themselves be injected as requirements into yet another component when it traverses the CompositionPhase, the phase of the Plexus component lifecycle where dependency injection typically takes place. Without getting too far into the details, these collections are not real components in the Plexus ...