Compile and Test with Different JDK Versions

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <executions>
                    <execution>
                        <id>java-1.4-compile</id>
                        <phase>compile</phase>
                        <goals>
                            <goal>compile</goal>
                        </goals>
                        <configuration>
                            <source>1.4</source>
                            <target>1.4</target>
                        </configuration>
                    </execution>
                    <execution>
                        <id>java-1.5-compile</id>
                        <phase>process-test-sources</phase>
                        <goals>
                            <goal>testCompile</goal>
                        </goals>
                        <configuration>
                            <source>1.5</source>
                            <target>1.5</target>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>