Datanucleus, JDO and executable jar - how to do it?

Question

I am developing a desktop app with Datanucleus and JDO for embedded H2 database. It all works fine when I run it from Eclipse, but it stops working when I try to make executable jar out of it. I get a following error:

org.datanucleus.exceptions.NucleusUserException: Persistence process has been specified to use a ClassLoaderResolver of name "jdo" yet this has not been found by the DataNucleus plugin mechanism. Please check your CLASSPATH and plugin specification.

Of course it shows that I have not configured something properly - what am I missing? If I was missing something big, it wouldn't work at all, so I am assuming it's a flawed executable jar. I have seen that error in other apps, like JPOX, where it was fixed, but without any solution given.

Whole error stacktrace:

Exception in thread "main" javax.jdo.JDOFatalInternalException: Unexpected exception caught.
        at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(JDOHelper.java:1193)
        at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:808)
        at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:701)
        at db.PersistenceManagerFilter.init(PersistenceManagerFilter.java:44)
        at Main.main(Main.java:26)
NestedThrowablesStackTrace:
java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at javax.jdo.JDOHelper$16.run(JDOHelper.java:1965)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.jdo.JDOHelper.invoke(JDOHelper.java:1960)
        at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(JDOHelper.java:1166)
        at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:808)
        at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:701)
        at db.PersistenceManagerFilter.init(PersistenceManagerFilter.java:44)
        at Main.main(Main.java:26)
Caused by: org.datanucleus.exceptions.NucleusUserException: Persistence process has been specified to use a ClassLoaderResolver of name "jdo" yet this has not been found by the DataNucleus plugin mechanism. Please check your CLASSPATH and plugin specification.
        at org.datanucleus.NucleusContext.<init>(NucleusContext.java:233)
        at org.datanucleus.NucleusContext.<init>(NucleusContext.java:196)
        at org.datanucleus.NucleusContext.<init>(NucleusContext.java:174)
        at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.<init>(JDOPersistenceManagerFactory.java:364)
        at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.createPersistenceManagerFactory(JDOPersistenceManagerFactory.java:294)
        at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.getPersistenceManagerFactory(JDOPersistenceManagerFactory.java:195)
        ... 12 more

The line it points to is PersistenceManagerFilter init method:

pmf = JDOHelper.getPersistenceManagerFactory(getProperties());

Properties file looks like that:

    javax.jdo.PersistenceManagerFactoryClass=org.datanucleus.api.jdo.JDOPersistenceManagerFactory
datanucleus.ConnectionDriverName=org.h2.Driver
datanucleus.ConnectionURL=jdbc:h2:datanucleus
datanucleus.ConnectionUserName=sa
datanucleus.ConnectionPassword=

I have all dependencies from maven, with a goal to deploy with dependencies. Dependencies are as stated on datanucleus page http://www.datanucleus.org/products/datanucleus/jdo/maven.html

Any ideas?

Whole project with maven dependencies deployed as executable jar file. — Paul
you mean you unjarred the DN jars and put everything in a single jar? — DataNucleus
I have bundled everything into big jar, all dependency jars into executable jar. With a maven-repo style structure inside the jar for dependencies. What is the correct way to bundle everything, so I can have working jar, with all dependencies working properly? — Paul
No, I do not have that in my MANIFEST file. I am not creating a plugin, just a standalone java app, so I didn't take a look at that section of documentation. I am not really sure what to put there then, bundle information too, or just define imports? — Paul

Krzysztof Zielinski Krzysztof Zielinski · Accepted Answer · 2012-04-13T08:02:16

Adding to DataNucleus answer.
To acheave what you need you should use maven-dependency-plugin
and add following to your pom.xml

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>2.4</version>
            <executions>
                <execution>
                    <id>copy-dependencies</id>
                    <phase>package</phase>
                    <goals>
                        <goal>copy-dependencies</goal>
                    </goals>
                    <configuration>
                        <outputDirectory>${project.build.directory}/jars</outputDirectory>
                        <overWriteReleases>false</overWriteReleases>
                        <overWriteSnapshots>false</overWriteSnapshots>
                        <overWriteIfNewer>true</overWriteIfNewer>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

Then the dependencies will be in target/jars dir.

To execute your app you use command:

Windows:
java -cp "yourFile.jar;jars/*" package.className

Linux:
java -cp "yourFile.jar:jars/*" package.className

NOTE: do not use jars/*.jar, this will not work

Datanucleus, JDO and executable jar - how to do it?

4 Answers