Maven 2: Different compilers for main and test

I'm in a situtation where different parts of my code need to use different compiler options. My main code often must be targetted for JDK 1.3, whereas I often use JDK 1.5 features (such as annotations and generics) in my test cases.

As I'm slowly peeling back the layers of Maven 2, I am finding solutions to these kinds of problems. Elegant (if somewhat verbose) solutions.

It turns out that you can not only provide a configuration for a particular plugin, but you can provide the configuration for that plugin in the context of a particular goal (or goals). So my solution was:

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                        <configuration>
                            <source>1.3</source>
                            <target>1.3</target>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

That is, when reaching the "compile" goal, use the provided configuration. In other compile situations, use defaults (in my case, inherited from a parent POM).

I'm still working out exactly how phase and goal interact. It seems like goals attach to different phases (to control order of execution) ... and you can name goals or phases on the command line. Then there's the question of how prefixes get mapped to plugins ... I feel I've only peeled back the first layer of this onion!