Wednesday, February 16, 2011

Mavenizing Red5: Antrun Plugin saves a lot of time

Red5Load will have an obvious dependency on Red5 libraries. Fortunately, building from source packages exactly what I need in a convenient archive (red5.jar). Unfortunately, I chose to layout Red5Load as a Maven 2 project. The Red5 team stubbornly insists on distributing their source as an Ant project with Ivy for dependency management. Don't get me wrong, I've nothing against Ant. I've just been working with Maven for so long that the Ant way of doing things is almost alien to me.

If that's not enough, previous experience indicates I'll eventually hit a wall delegating to or extending Red5 classes and will have to resort to modifying the source. If I chose to fully mavenize the project, I'll drive myself crazy trying to keep the Red5 drop tracking well with the vendor source. What I need is a way to kick off the drop's Ant build and collect the resulting jar(s) as resolvable Maven artifacts.

Enter maven-antrun-plugin
. This convenient little tool allows me to bind appropriate Ant targets to phases in a Maven build's lifecycle. I've chosen to handle, obviously, clean, compile and package.


Each execution targets the same goal, antrun:run.




Cleaning is fairly trivial, requiring only executing ant against the target clean.



To compile, we simply call ant
with no specified target. The Red5 project defines a build.xml configuration that Ant automatically picks up, but we could easily provide our own and specify an antfile
attribute to the ant tag.



Packaging is a little more interesting. Since Maven isn't actually handling archiving, we have to coax Maven into injecting the resulting jar (or jars) from the Ant build under resolvable coordinates. This is where the attachartifact tag proves extremely useful.



You can read up on classifiers here, but for now the important thing to take away is that our complete POM will configure three artifacts in our local repository:

  1. red5-1.0.0-SNAPSHOT.pom
  2. red5-1.0.0-SNAPSHOT-server.jar
  3. red5-1.0.0-SNAPSHOT-boot.jar