How do you transition from using Eclipse for your builds to using Ant

I have a spring web application in Eclipse Helios. I use Ant for my builds on other projects but am not familiar with initially setting up Ant build files. Is there a painless way to make the transition from using Eclipse to do my builds, to creating an Ant build file and any supporting files? I tried copying a basic Ant build file into my application but I'm not sure if it's even close to what I need. I've included it below. It's giving me this error when I run it.

BUILD FAILED
C:\..\..\workspace\..\build.xml:21: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.

My syst开发者_Go百科em JAVA_HOME path is set to 'C:\Program Files\Java\jdk1.7.0\bin'

<?xml version="1.0" encoding="UTF-8"?>
<project name="projectName" default="dist" basedir=".">
<description>
    build file
  </description>
<!-- set global properties for this build -->
<property name="src" location="src"/>
<property name="build" location="build"/>
<property name="dist"  location="dist"/>

<target name="init">
  <!-- Create the time stamp -->
  <tstamp/>
  <!-- Create the build directory structure used by compile -->
  <mkdir dir="${build}"/>
</target>

<target name="compile" depends="init"
    description="compile the source " >
<!-- Compile the java code from ${src} into ${build} -->
<javac srcdir="${src}" destdir="${build}"/>
</target>

<target name="dist" depends="compile"
    description="generate the distribution" >
<!-- Create the distribution directory -->
<mkdir dir="${dist}/lib"/>

<!-- Put everything in ${build} into the News-${DSTAMP}.jar file -->
<jar jarfile="${dist}/lib/ProjectName-${DSTAMP}.jar" basedir="${build}"/>
</target>

<target name="clean"
    description="clean up" >
<!-- Delete the ${build} and ${dist} directory trees -->
<delete dir="${build}"/>
<delete dir="${dist}"/>
</target>
</project>

---

Don't include the bin folder in your JAVA_HOME

Try this:

C:\Program Files\Java\jdk1.7.0