<javac srcdir="${src.dir}" destdir="${classes.dir}" debug="true" debuglevel="lines,vars,source">

..........

</javac>

-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5432

<java classname="..." fork="true">
  <jvmarg value="-Xdebug" />
  <jvmarg value="-Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5432" />
  ...
</java>

Name: Debug Ant
Project: <Select your project where debug files are kept>
Host: localhost
Port: 8787

Window -> Show View -> Others -> Servers

set ANT_OPTS=%ANT_OPTS% -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5432

Toolbar >> Run >> Debug Configurations >> + >>

Name: Debug_Ant
Project: active-eclipse-project
Host:localhost
Port:5432