Using JDO Persistent classes from a separate module with datanucleus maven plugin

问题

I have a working application that persists to a database using JDO - I want to use a PersistenceCapable class that's in a second java module. Although the app compiles a simple test gives the error:

The class "com.hello.world.Foo" is not persistable This means that it either hasnt been enhanced, or that the enhanced version of the file is not in the CLASSPATH (or is hidden by an unenhanced version), or the Meta-Data/annotations for the class are not found.

Ok, so the enhancer plugin is not running on the classes in the second module. I'm not sure what i need to do to point the enhancer at that module during the build.

ParentProject
Second Module: com.hello.world.Foo

ParentProject pom.xml with relevant parts - problem is how do i point the enhancer at the second module containing my persistent class?

    <dependencies>


        <dependency>
            <groupId>Second Module</groupId>
            <artifactId>Second Module</artifactId>
            <version>1.0-SNAPSHOT</version>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>javax.jdo</groupId>
            <artifactId>jdo-api</artifactId>
            <version>3.0.1</version>
        </dependency>
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-core</artifactId>
            <version>[3.2.0, 3.2.99)</version>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-api-jdo</artifactId>
            <version>[3.2.0, 3.2.99)</version>
        </dependency>
        <dependency>
            <groupId>org.datanucleus</groupId>
            <artifactId>datanucleus-rdbms</artifactId>
            <version>[3.2.0, 3.2.99)</version>
            <scope>runtime</scope>
        </dependency>


    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.datanucleus</groupId>
                <artifactId>datanucleus-maven-plugin</artifactId>
                <version>3.3.0-release</version>
                <configuration>
                    <api>JDO</api>
                    <props>${basedir}/datanucleus.properties</props>
                    <log4jConfiguration>${basedir}/log4j.properties</log4jConfiguration>
                    <verbose>true</verbose>
                </configuration>
                <executions>
                    <execution>
                        <phase>process-classes</phase>
                        <goals>
                            <goal>enhance</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>
</project>

回答1:

got it - i had to add the exact same pom.xml config in the question to the second module and do a mvn install to get those classes enahnced before compiling the parent module. Working on both Jetty and GAE. I thought, wrongly, that the parent module would enhance classes included in the module dependencies.

Thanks for your help DataNucleus!

来源：https://stackoverflow.com/questions/19431412/using-jdo-persistent-classes-from-a-separate-module-with-datanucleus-maven-plugi

标签

java

maven

datanucleus