Below is the code snippet for the Ant target that is doing loadtime instrumentation through a special classloader. Basically, the Ant target one.test.aop using the bootclass loader generated by the Ant target generateClassLoader to run an individual test. Note that since JBossAop 1.3, a new GenerateInstrumentedClassLoader has been used since the previous SystemClassLoader is error prone.

   <target name="generateClassLoader" description=
           "Generate a new modified class loader so we can perform load time instrumentation">
      <property name="build.bootclasspath" value="${output}/gen-bootclasspath"/>
      <java classname="org.jboss.aop.hook.GenerateInstrumentedClassLoader">
         <classpath>
            <path refid="aop.classpath"/>
         </classpath>
         <arg value="${build.bootclasspath}"/>
      </java>
      <path id="bootclasspath">
         <pathelement location="${build.bootclasspath}"/>
         <path refid="aop.classpath"/>
      </path>
      <property name="bootclasspath" refid="bootclasspath"/>
   </target>

   <!-- eg. ant run.examples -Dtest=org.jboss.test.cache.test.local.NoTxUnitTestCase -->
   <target name="one.test.aop" depends="compile, generateClassLoader" 
   description="run one junit test case.">
      <junit printsummary="yes" timeout="${junit.timeout}" fork="yes">
         <jvmarg value="-Djboss.aop.path=${output}/etc/META-INF/jboss-aop.xml"/>
         <jvmarg value="-Xbootclasspath/p:${bootclasspath}"/>
         <!-- jvmarg value="-Dbind.address=${bind.address}"/ -->
         <classpath path="${output}/etc" />
         <sysproperty key="log4j.configuration" value="file:${output}/etc/log4j.xml" />
         <classpath refid="lib.classpath"/>
         <classpath path="${build}"/>
         <formatter type="xml" usefile="true"/>
         <test name="${test}" todir="${reports}"/>
      </junit>
  </target>   

If you are running JDK5.0, you can also use the javaagent option that does not require a separate Classloader. Here are the ant snippet from one-test-aop50, for example.

   <target name="one.test.aop50" depends="compile, generateClassLoader"
   description="run one junit test case.">
     <junit printsummary="yes" timeout="${junit.timeout}" fork="yes">
        <jvmarg value="-Djboss.aop.path=${output}/resources/jboss-aop.xml"/>
        <jvmarg value="-javaagent:${lib-50}/jboss-aop-jdk50.jar"/>
        <classpath path="${output}/etc" />
        <sysproperty key="log4j.configuration" value="file:${output}/etc/log4j.xml" />
        <classpath refid="lib.classpath.50"/>
        <classpath refid="build.classpath.50"/>
        <formatter type="xml" usefile="true"/>
        <test name="${test}" todir="${reports}"/>
     </junit>
   </target>