| Apache OpenJPA - Metamodel generator (mmg) readme |
| Licensed under Apache License 2.0 - http://www.apache.org/licenses/LICENSE-2.0 |
| -------------------------------------------------------------------------------- |
| |
| JPA 2.0 provides an utility to generate canonical metamodel for each persistent domain entity. |
| This brief note describes how to generate these canonical metamodel classes. |
| |
| The canonical metamodel classes are generated during compilation of persistent domain entity classes. |
| The generation process depends on Annotation Processing facility available in JDK6. Naturally, this |
| process *only* works if the persistent domain entity classes are compiled with a JDK6 compiler. |
| |
| Effectively, the process appears to be normal compilation process with a specialized Annotation Processor |
| |
| $ javac -classpath %CLASSPATH% <javac options> <mmg options> <*.java source files> |
| |
| |
| Compiler Classpath |
| ------------------ |
| The compiler classpath must include OpenJPA libraries. |
| |
| mmg options |
| ----------- |
| These options specify the Annotation processor to be used as well as options for the processor. The only mandatory |
| option is |
| -processor org.apache.openjpa.persistence.meta.AnnotationProcessor6 |
| |
| The other options qualify the Annotation processor itself and specified with -A<option>=<value> syntax |
| |
| -Alog log level. Permissible values are TRACE, INFO and WARN. |
| Default is INFO. |
| -Aout the directory location of the generated canonical model source output files. |
| Default is the current directory. |
| -Asource compatibility level of the generated canonical model source code. Permissible values are 5 and 6. |
| Default is 6. |
| -Aheader flags if a header is created for the generated source code. Permissible values are true and false. |
| Default is true. |
| |
