I think the problem is your taskdef, it's missing the path containing the dbunit jar:
<taskdef name="dbunit" classname="org.dbunit.ant.DbUnitTask" classpathref="libs.dir"/>
Question
It doesn't work in ant, I'd like to run some classes that extend DatabaseTestCase
<path id="libs.dir">
<fileset dir="lib" includes="**/*.jar" />
</path>
<taskdef name="dbunit"
classname="org.dbunit.ant.DbUnitTask"/>
<!-- run all tests in the source tree -->
<junit printsummary="yes" haltonfailure="yes">
<formatter type="xml"/>
<batchtest fork="yes" todir="${reports.tests}">
<fileset dir="${src.tests}">
<include name="**/*Test*.java"/>
</fileset>
</batchtest>
</junit>
It says the following:
Buildfile: D:\kariakin\jdbc_task\build.xml
BUILD FAILED
D:\kariakin\jdbc_task\build.xml:15: taskdef class org.dbunit.ant.DbUnitTask cannot be found
using the classloader AntClassLoader[]
Solution
I think the problem is your taskdef, it's missing the path containing the dbunit jar:
<taskdef name="dbunit" classname="org.dbunit.ant.DbUnitTask" classpathref="libs.dir"/>