Calling a java class as ant target

Here is the way to do it

classname: is filename of java :Ex: AutomationFileSequence
 arg: Any arguments if required to run the class needs to be mentioned here.

<target name="run_PostData" >
  <java fork="false" failonerror="yes" classname="com.qa.automation.main.AutomationFileSequence" classpathref="classpath"> 
            <arg line="${basedir}/Automation_PostData.properties"/>
    <arg line="PostData"/>
            </java>
            </target>