ant run target if file has specifc suffix - file

Question

I pass a filename to ant script via
ant -Dfilepath=/foo/bar/foobar.suffix
I want to copy it to a destination and if it is a .js file generate a compiled version of it.
This works but currently the compile task runs on all files not just .js file.
How do I exclude non .js files in the "runjscompile" task?
In a fileset I would do this (but I don't get how to apply this on the task):
<fileset dir="${foo}" casesensitive="yes">
<exclude name="**/*.min.js" />
<include name="**/*.js" />
</fileset>
My build.xml:
<?xml version="1.0" encoding="UTF-8"?>
<project name="test" basedir="." default="build">
<taskdef name="jscomp" classname="com.google.javascript.jscomp.ant.CompileTask" classpath="/home/bar/bin/compiler.jar" />
<taskdef resource="net/sf/antcontrib/antlib.xml">
<classpath>
<pathelement location="/usr/share/java/ant-contrib.jar" />
</classpath>
</taskdef>
<property name="serverRoot" value="/home/bar/server/public_html" />
<property name="foo" value="${serverRoot}/foo/" />
<property name="workspaceRoot"
value="/home/bar/Zend/workspaces/DefaultWorkspace/" />
<property name="foo_service" value="${workspaceRoot}/foo_service/" />
<property name="filepath" value="${filepath}" />
<target name="build" depends="transferFile, runjscompile" />
<target name="transferFile" description="overwrite old file">
<basename property="filename" file="${filepath}" />
<dirname property="path" file="${filepath}" />
<pathconvert property="path.fragment" pathsep="${line.separator}">
<propertyresource name="path" />
<mapper type="regexp" from="^/[^/]+/(.*)" to="\1" />
</pathconvert>
<echo message="copy ${workspaceRoot}${filepath} to ${foo}${path.fragment}${filename}" />
<copy file="${workspaceRoot}${filepath}" tofile="${foo}${path.fragment}${filename}"
overwrite="true" force="true" />
<property name="destFile" value="${foo}${path.fragment}${filename}" />
</target>
<target name="runjscompile">
<echo message="compile ${destFile}" />
<basename property="file" file="${destFile}" />
<basename property="prefix" file="${destFile}" suffix=".js" />
<dirname property="directory" file="${destFile}" />
<echo message="Compressing file ${file} to ${directory}/${prefix}.min.js" />
<jscomp compilationLevel="simple" debug="false" output="${directory}/${prefix}.min.js" forceRecompile="true">
<sources dir="${directory}">
<file name="${file}" />
</sources>
</jscomp>
</target>
</project>

Answer 1

Add another target which checks the file suffix with a <condition> and sets a property if it matches, then make the jscompile target conditional on that. Following your fileset example you probably want something like:
<target name="check.js">
<condition property="do.jscompile">
<!-- check for filepath that ends .js but not .min.js -->
<matches string="${filepath}" pattern=".*(?<!\.min)\.js$$" />
</condition>
</target>
<target name="build" depends="check.js, transferFile, runjscompile" />
<target name="runjscompile" if="do.jscompile">