java - Only create classes with XJCFacade when schema changes -

<target name="buildbbastjarfromxsd">     <echo message="generating jar xsd restservice"/>     <java classname="com.sun.tools.internal.xjc.xjcfacade">         <arg value="-d" />         <arg value="${dev.location}"/>         <arg "${dev.location}/path/dev.xsd" />     </java>     <javac srcdir="${dev.location}" destdir="${dev.location}"         debug="on" includeantruntime="false"     >         <classpath refid="dev.classpath"/>     </javac>     <jar         destfile="${dev.location}/webcontent/web-inf/rest.jar"         basedir="${bbct.location}"         includes="**/*.class"     /> </target> 

how edit above ant task in build.xml make sure above scripts of java(xjcfacade) run if xsd-named dev.xsd gets modified?

and want make sure javac , jar run if java(xjcfacade) runs.