Using APT utility with Empire

APT (Annotation Processing Tool) is provided by Sun and does compile-time scanning of Java source code to pull out information on the annotations used in the source. By attaching an AnnotationProcessor & AnnotationProcessorFactory to APT, you can get this processing information and use it to build new files, Java source, properties, xml, etc. which contain information that can be used by your application at runtime.

We provide implementations for the APT tool to grab information JPA & Empire annotations that are used in the system. This information is stored locally in simple Java properties format and when provided to Empire, will be used to enhance the runtime of the system.

APT is distributed in tools.jar with the JDK starting with Java 5. For more information about APT, visit Sun’s reference page.

Usage

apt -cp <path omitted for brevity> -factory com.clarkparsia.empire.util.apt.EmpireAnnotationProcessorFactory src/my/package/*.java src/my/package/api/*.java

This will output a file called “empire.config” into the directory where you ran APT from. You will need to rebuild
this file each time you change annotations on your Java classes, or add new classes.