Using the openjpa-maven-plugin
The full OpenJPA Maven plugin documentation can be found here.
For example, to enhance you source entity classes after they have been
compiled (but exclude any POJO classes that rely upon orm.xml maappings),
add the openjpa-maven-plugin to the section of your pom.xml, like -
<build>
...
<plugin>
<groupId>org.apache.openjpa</groupId>
<artifactId>openjpa-maven-plugin</artifactId>
<version>3.1.2</version>
<configuration>
<includes>**/entities/*.class</includes>
<excludes>**/entities/XML*.class</excludes>
<addDefaultConstructor>true</addDefaultConstructor>
<enforcePropertyRestrictions>true</enforcePropertyRestrictions>
</configuration>
<executions>
<execution>
<id>enhancer</id>
<phase>process-classes</phase>
<goals>
<goal>enhance</goal>
</goals>
</execution>
</executions>
</plugin>
...
</build>
There are other goals available to create the Entity to SQL mapping and
Entity to XML Schema mapping, which are documented under the Goals section
on the plugin website.
Using the maven-antrun-plugin
You can use the maven-antrun-plugin to launch the OpenJPA enhancer task
using ANT. The steps are nearly identical to the ones for Enhancing with ANT
(again, you may not need to move the persistence.xml file to the build
directory, but I did for this write-up).
<build>
<!-- Copy the persistence.xml file to the build dir -->
<!-- You can skip this step if you put the persistence.xml in src/main/resources/META-INF instead of src/main/java/META-INF -->
<resources>
<resource>
<directory> src/main/java </directory>
<includes>
<include> **/*.xml </include>
</includes>
</resource>
</resources>
<plugins>
.....
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.2</version>
<executions>
<execution>
<phase>process-classes</phase>
<configuration>
<tasks>
<taskdef name="openjpac" classname="org.apache.openjpa.ant.PCEnhancerTask" classpathref="maven.compile.classpath"/>
<openjpac>
<classpath refid="maven.compile.classpath"/>
</openjpac>
</tasks>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
....
</build>
