Import tool: does not compile with Java 7

The import tool build fails when using Java 7. The following error is logged:

[ERROR] Failed to execute goal com.sun.tools.jxc.maven2:maven-jaxb-schemagen-plugin:1.2:generate (default) on project import-tool-import-components: Execution default of goal com.sun.tools.jxc.maven2:maven-jaxb-schemagen-plugin:1.2:generate failed: A required class was missing while executing com.sun.tools.jxc.maven2:maven-jaxb-schemagen-plugin:1.2:generate: com/sun/mirror/apt/AnnotationProcessorFactory
[ERROR] -----------------------------------------------------
[ERROR] realm = plugin>com.sun.tools.jxc.maven2:maven-jaxb-schemagen-plugin:1.2
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy
[ERROR] urls[0] = file:/home/mathijs/.m2/repository/com/sun/tools/jxc/maven2/maven-jaxb-schemagen-plugin/1.2/maven-jaxb-schemagen-plugin-1.2.jar
[ERROR] urls[1] = file:/home/mathijs/.m2/repository/org/codehaus/plexus/plexus-utils/1.1/plexus-utils-1.1.jar
[ERROR] urls[2] = file:/home/mathijs/.m2/repository/junit/junit/3.8.1/junit-3.8.1.jar
[ERROR] urls[3] = file:/home/mathijs/.m2/repository/javax/xml/bind/jaxb-api/2.0/jaxb-api-2.0.jar
[ERROR] urls[4] = file:/home/mathijs/.m2/repository/com/sun/xml/bind/jaxb-impl/2.0.2/jaxb-impl-2.0.2.jar
[ERROR] urls[5] = file:/home/mathijs/.m2/repository/ant/ant/1.6.5/ant-1.6.5.jar
[ERROR] urls[6] = file:/home/mathijs/.m2/repository/com/sun/xml/bind/jaxb-xjc/2.0.2/jaxb-xjc-2.0.2.jar
[ERROR] urls[7] = file:/home/mathijs/.m2/repository/javax/activation/activation/1.1/activation-1.1.jar
[ERROR] urls[8] = file:/home/mathijs/.m2/repository/javax/xml/bind/jsr173_api/1.0/jsr173_api-1.0.jar
[ERROR] Number of foreign imports: 1
[ERROR] import: Entry[import from realm ClassRealm[project>org.onehippo.forge.import-tool:import-tool:1.05.02-SNAPSHOT, parent: ClassRealm[maven.api, parent: null]]]
[ERROR]
[ERROR] -----------------------------------------------------: com.sun.mirror.apt.AnnotationProcessorFactory
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/PluginContainerException
[ERROR]
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR] mvn <goals> -rf :import-tool-import-components