1. Add additional command line arguments for <javac> task:
<javac srcdir="${dist}/trsWeb" destdir="${dist}/build/trsWeb"
fork="true" classpath="${compile_classpath}" source="1.5" target="1.5"
nowarn="true">
<compilerarg value="-J-Duser.language=en"/>
</javac>
2. if...else...
<if>
<equals arg1="${hello}" arg2="true"/>
<then>
<echo >${hello} value is true</echo>
</then>
<elseif>
<equals arg1="${hello}" arg2="false"/>
<then>
<echo >${hello} value is false</echo>
</then>
</elseif>
<else>
<echo >${hello} value is unknowe</echo>
</else>
</if>
3. placeholder variables in build.xml
build.properties
--------------------
key=value
build.xml
--------------------
<project name="TestAntPlaceHolder" default="echo" basedir=".">
<property file="build.properties" /> <---- mandatory, no default property file biult-in.
<target name="echo">
<echo message="I'm ${key}..."/>
</target>
</project>