stumbling blocks galore while trying to run org.hibernate.tool.ant.EnversHibernateToolTask

问题

I'm trying to run org.hibernate.tool.ant.EnversHibernateToolTask as suggested in the rather terse guide to Envers (2nd line of table, Documentation has a link to a PDF). Here's my ant task tweaked so it successfully finds org.hibernate.tool.ant.EnversHibernateToolTask and org.hibernate.tool.ant.HibernateToolTask; now it can't find org.apache.tools.ant.Task and I have the sinking feeling I am doing something wrong.

<target name="schemaexport" depends="init"
        description="Exports a generated schema to DB and file">
<taskdef name="hibernatetool"
    classname="org.hibernate.tool.ant.EnversHibernateToolTask"
        classpath=".;C:\appl\Java\jre6u13\lib\ext\envers-1.2.0.ga-hibernate-3.3.jar;C:\appl\Java\jre6u13\lib\ext\hibernate-tools.jar" />
<!--classpathref="${schema.classpath}"/>-->
<hibernatetool destdir=".">
    <classpath>
        <fileset refid="lib.hibernate" />
        <path location="${build.dir}" />
    </classpath>
<jpaconfiguration persistenceunit="ConsolePU" />
<hbm2ddl
    drop="false"
    create="true"
    export="false"
    outputfilename="versioning-ddl.sql"
    delimiter=";"
    format="true"/>
</hibernatetool>
</target>

I've never done a custom ant task before so I'm probably missing something really simple. Any suggestions? I don't know what to put for the classpath in the hibernatetool task, which I can't find any documentation for beyond rudimentary javadoc.

edit: ok, some specific Q's to try to get to this piecemeal...

1. which jar is org.apache.tools.ant.Task supposed to be in, and why can't ant find it?
2. where are the docs on how to use HibernateToolTask? (I assume EnversHibernateToolTask is supposed to work the same)

update (2009-06-18): OK, I finally screwed up my courage to try to make some progress on this and made some headway. I can get it to almost work by doing two things:

1. run ant schemaexport from the command line, rather than from within Eclipse, to run my schemaexport target. (ant in Eclipse can't seem to find org/apache/tools/ant/Task and I don't know how to set the Ant classpath in eclipse (distinct from the classpath in the taskdef item; somehow I have to tell ant to use a classpath to find its own damn class when it runs a custom task. this is insane.... grrr...)

2. ensuring my classpath contains all the jars that I just take for granted by sticking in my JRE's /lib/ext directory:

   • envers-1.2.0.ga-hibernate-3.3.jar
   • hibernate3.jar
   • hibernate-tools.jar
   • slf4j-log4j12-1.5.6.jar
   • slf4j-api-1.5.6.jar
   • log4j-1.2.15.jar

Now I get a new problem:

BUILD FAILED C:\deka\proj\java\test-database\build.xml:61: Problems in creating a configurati on for JPA. Have you remembered to add hibernate EntityManager jars to the class path ?

[[[[[scream]]]]]

update It appears I also needed

• hibernate-entitymanager.jar
• hibernate-annotations.jar

and I STILL get classloader errors:

BUILD FAILED
java.lang.NoClassDefFoundError: javax/persistence/PersistenceException
        at java.lang.Class.getDeclaredConstructors0(Native Method)
        at java.lang.Class.privateGetDeclaredConstructors(Class.java:2389)
        at java.lang.Class.getConstructor0(Class.java:2699)
        at java.lang.Class.newInstance0(Class.java:326)
        at java.lang.Class.newInstance(Class.java:308)
        at org.hibernate.tool.ant.JPAConfigurationTask.createConfiguration(JPACo
nfigurationTask.java:33)
        at org.hibernate.tool.ant.ConfigurationTask.getConfiguration(Configurati
onTask.java:54)

How can I run this w/o having to use a J2EE server?!?!?!?!?!? What other JAR files do I need? I am really confused and frustrated.

update (2009-06-23): I finally got a successful build. Seems like you need:

* envers-1.2.0.ga-hibernate-3.3.jar
* hibernate3.jar
* hibernate-tools.jar
* slf4j-log4j12-1.5.6.jar
* slf4j-api-1.5.6.jar 
* log4j-1.2.15.jar
* dom4j-1.6.1.jar
* hibernate-commons-annotations.ja
* a JAR containing JTA classes (Sun doesn't have a JAR file but you can download the [class files][3] yourself and make a JAR file out of it)
* a JAR containing JPA classes (I used toplink-essentials.jar from the glassfish project, per [this SO question][4])
* commons-logging-1.1.1.jar
* freemarker.jar

and made sure to use

<annotationconfiguration configurationfile="${some_path}/hibernate.cfg.xml"/>

instead of the <jpaconfiguration> item included in the sample ant task. It still doesn't work properly though, I don't get the envers tables included. :(

回答1:

EnversHibernateToolTask extends HibernateToolTask. All I needed to do was the following:

<taskdef name="hibernatetool"
classname="org.hibernate.tool.ant.EnversHibernateToolTask"
        classpath="envers-1.2.0.ga-hibernate-3.3.jar" />

Otherwise it would be helpful to see the output of the ant file you've pasted.

回答2:

u might need ejb3-persistence-1.0.2.GA.jar

来源：https://stackoverflow.com/questions/952908/stumbling-blocks-galore-while-trying-to-run-org-hibernate-tool-ant-envershiberna