NullPointerException when switching from hibernate-maven-plugin version 2.2 to version 3.0

Question

I am updating the versions of my pom.xml dependencies and I've run into a vague error when I change the version of the hibernate3-maven-plugin from

<plugin>
    <!-- Run "mvn hibernate3:hbm2ddl" to generate schema -->
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>hibernate3-maven-plugin</artifactId>
    <version>2.2</version>
</plugin>

to

<plugin>
    <!-- Run "mvn hibernate3:hbm2ddl" to generate schema -->
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>hibernate3-maven-plugin</artifactId>
    <version>3.0</version>
</plugin>

With version 2.2, everything compiles successfully, and

mvn hibernate3:hbm2ddl

creates the correct schema from annotated classes.

Changing nothing else but the version results in the following error when I run the hbm2ddl command again:

[ERROR] Failed to execute goal org.codehaus.mojo:hibernate3-maven-plugin:3.0:hbm2ddl (default-cli) on project myProject: There was an error creating the AntRun task. NullPointerException -> [Help 1]

The full stack trace is as follows:

[ERROR] Failed to execute goal org.codehaus.mojo:hibernate3-maven-plugin:3.0:hbm2ddl (default-cli) on project myProject: There was an error creating the AntRun task. NullPointerException -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:hibernate3-maven-plugin:3.0:hbm2ddl (default-cli) on project myProject: There was an error creating the AntRun task.
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
    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:319)
    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:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    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)
Caused by: org.apache.maven.plugin.MojoExecutionException: There was an error creating the AntRun task.
    at org.codehaus.mojo.hibernate3.AbstractHibernateMojo.execute(AbstractHibernateMojo.java:84)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
    ... 19 more
Caused by: java.lang.NullPointerException
    at org.codehaus.plexus.configuration.DefaultPlexusConfiguration.add(DefaultPlexusConfiguration.java:174)
    at org.codehaus.plexus.configuration.DefaultPlexusConfiguration.addChild(DefaultPlexusConfiguration.java:150)
    at org.codehaus.mojo.hibernate3.util.PlexusConfigurationUtils.setHibernateConfiguration(PlexusConfigurationUtils.java:289)
    at org.codehaus.mojo.hibernate3.util.PlexusConfigurationUtils.parseHibernateTool(PlexusConfigurationUtils.java:67)
    at org.codehaus.mojo.hibernate3.AbstractHibernateToolMojo.getConfiguration(AbstractHibernateToolMojo.java:60)
    at org.codehaus.mojo.hibernate3.AbstractHibernateMojo.execute(AbstractHibernateMojo.java:76)
    ... 21 more

If I go back to version 2.2, everything works fine. And because I am not looking to upgrade for any particular reason other than simply having the most up-to-date dependencies, I'll stick with 2.2 for the time being.

Hopefully someone can shed some light on this!

Answer 1

Updated the plugin to the following and it worked:

<plugin>
    <!-- Run "mvn hibernate3:hbm2ddl" to generate schema -->
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>hibernate3-maven-plugin</artifactId>
    <version>${hibernate3.maven.plugin.version}</version>

    <configuration>
        <hibernatetool>
            <annotationconfiguration propertyfile="src/main/resources/${hibernate.properties}" />
            <hbm2ddl update="true" create="true" export="false"
                     outputfilename="${hibernate.hbm2ddl.sqlfile}" format="true"
                     console="true" />
        </hibernatetool>
    </configuration>
</plugin>