My project only builds with JDK 1.4

Because SonarQube can only run with JDK 1.6 or higher, some configuration should be added to the pom.xml to indicate that the project requires JDK1.4:

<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <configuration>
        <source>1.4</source>
        <target>1.4</target>
    </configuration>
</plugin>