Google App Engine with Spring Roo

Question

Here is the Roo script that I am running. Using version spring-roo-1.2.2.RELEASE from the shell both in terminal and in STS.

persistence setup --provider DATANUCLEUS --database GOOGLE_APP_ENGINE --applicationId roo-gae

entity jpa --class ~.domain.Wheel --testAutomatically
field string --fieldName code --notNull --unique

entity jpa --class ~.domain.Car --testAutomatically
field string --fieldName name --notNull --unique
field string --fieldName color --notNull
field reference --fieldName wheel --type ~.domain.Wheel --notNull

perform tests

I don't make any manual changes to the project, but the perform tests fails with this message:

[ERROR] Failed to execute goal org.datanucleus:maven-datanucleus-plugin:3.0.2:enhance (default) on project test: Error executing DataNucleus tool org.datanucleus.enhancer.DataNucleusEnhancer: InvocationTargetException: Plugin (Bundle) "org.datanucleus.enhancer" is already registered. Ensure you dont have multiple JAR versions of the same plugin in the classpath. The URL "file:/home/timh/.m2/repository/org/datanucleus/datanucleus-enhancer/3.1.0-m1/datanucleus-enhancer-3.1.0-m1.jar" is already registered, and you are trying to register an identical plugin located at URL "file:/home/timh/.m2/repository/org/datanucleus/datanucleus-enhancer/3.0.1/datanucleus-enhancer-3.0.1.jar." -> [Help 1]
[ERROR] .Car roo> 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] .Car roo> 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoExecutionException

I see datanucleus-enhancer-3.0.1.jar on the classpath but I think that datanucleus-enhancer-3.1.0-m1.jar is being downloaded by the plugin. Does anyone know a solution or a workaround to this issue?

Answer 1

This can be corrected by manually specifying the datanucleus enhancer plugin version by adding the following under the dependencies for the maven-datanucleus-plugin in your pom.xml.

<dependency>
 <groupId>org.datanucleus</groupId>
 <artifactId>datanucleus-enhancer</artifactId>
 <version>3.1.0-m2</version>
</dependency>

Your final maven-dataanucleus-plugin configuration can appear like below once its added.

<plugin>
<groupId>org.datanucleus</groupId>
<artifactId>maven-datanucleus-plugin</artifactId>
<version>3.0.2</version>
<configuration>
        <fork>false</fork>
        <log4jConfiguration>${basedir}/src/main/resources/log4j.properties</log4jConfiguration>
        <mappingIncludes>**/*.class</mappingIncludes>
        <verbose>true</verbose>
        <enhancerName>ASM</enhancerName>
        <api>JPA</api>
    <mappingExcludes>**/CustomRequestFactoryServlet.class, **/GaeAuthFilter.class</mappingExcludes>
</configuration>
<executions>
    <execution>
        <phase>compile</phase>
        <goals>
            <goal>enhance</goal>
        </goals>
    </execution>
</executions>
<dependencies>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-core</artifactId>
        <version>3.0.10</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-enhancer</artifactId>
        <version>3.1.0-m2</version>
    </dependency>
    <dependency>
        <groupId>org.datanucleus</groupId>
        <artifactId>datanucleus-api-jpa</artifactId>
        <version>3.0.9</version>
    </dependency>
</dependencies>
</plugin>

Cheers.