Eclipselink 2.5 Metamodel Generation using Maven

Question

I would like to know how to generate static metamodels using Maven and Eclipselink 2.5. It worked fine by adding this lines to pom.xml when running Eclipselink 2.4.

// Generate meta model for eclipselink 2.4 (does not work for 2.5)
    <plugin>
                    <groupId>org.bsc.maven</groupId>
                    <artifactId>maven-processor-plugin</artifactId>
                    <version>1.3.1</version>
                    <executions>
                        <execution>
                            <id>process</id>
                            <goals>
                                <goal>process</goal>
                            </goals>
                            <phase>generate-sources</phase>
                            <configuration>
                                <compilerArguments>-Aeclipselink.persistencexml=src/main/resources/META-INF/persistence.xml</compilerArguments>
                                <processors>
                                    <processor>org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor</processor>
                                </processors>
                                <outputDirectory>${project.build.directory}/generated-sources/meta-model</outputDirectory>
                            </configuration>
                        </execution>
                    </executions>
                </plugin>

But it seems like something has changed since 2.4 cause I get following error:

[INFO] javac option: -proc:only
[INFO] javac option: -Aeclipselink.persistencexml=src/main/resources/META-INF/persistence.xml
[INFO] javac option: -processor
[INFO] javac option: org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor
[INFO] javac option: -s
[INFO] javac option: /home/asdf/target/generated-sources/meta-model
[INFO] diagnostic error: Annotation processor 'org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor' not found
[INFO] diagnostic warning: Annotation processing without compilation requested but no processors were found.
[ERROR] execute error
java.lang.Exception: error during compilation
    at org.bsc.maven.plugin.processor.AbstractAnnotationProcessorMojo.executeWithExceptionsHandled(AbstractAnnotationProcessorMojo.java:183)
    at org.bsc.maven.plugin.processor.AbstractAnnotationProcessorMojo.execute(AbstractAnnotationProcessorMojo.java:96)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:606)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)

Can you guys out there help me? =)

B.R

Answer 1

It appears that they've moved the CanonicalModelProcessor class to it's own maven artifact:

<dependency>
  <groupId>org.eclipse.persistence</groupId>
  <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId>
  <version>2.5.0</version>
</dependency>

The following maven-processor-plugin configuration works for me:

        <plugin>
            <groupId>org.bsc.maven</groupId>
            <artifactId>maven-processor-plugin</artifactId>
            <version>2.2.4</version>
            <executions>
                <execution>
                    <id>eclipselink-jpa-metamodel</id>
                    <goals>
                        <goal>process</goal>
                    </goals>
                    <phase>generate-sources</phase>
                    <configuration>
                        <processors>
                            <processor>org.eclipse.persistence.internal.jpa.modelgen.CanonicalModelProcessor</processor>
                        </processors>
                        <outputDirectory>${project.build.directory}/generated-sources/meta-model</outputDirectory>
                    </configuration>
                </execution>
            </executions>
            <dependencies>
                <dependency>
                    <groupId>org.eclipse.persistence</groupId>
                    <artifactId>org.eclipse.persistence.jpa.modelgen.processor</artifactId>
                    <version>2.5.0</version>
                    <scope>provided</scope>
                </dependency>
            </dependencies>
        </plugin>

Very important note: the metamodel is generated only if the entities are declared in the persistence unit. It doesn't work with discovered entities.