build.xml

<project name="appengine-runnabletask">
  <path id="project.classpath">
    <fileset dir="lib">
      <include name="scala/*.jar" />
      <include name="*.jar" />
      <include name="*.jar" />
    </fileset>
	<fileset dir="appengine-java-sdk">
	  <include name="lib/user/*.jar"/>
	</fileset>
  </path>

  <property name="scala-compiler.jar" value=""/>
  <taskdef resource="scala/tools/ant/antlib.xml">
    <classpath>
      <pathelement location="lib/scala/scala-compiler.jar" />
      <pathelement location="lib/scala/scala-library.jar" />
    </classpath>
  </taskdef>

  <property name="dist" location="dist"/>
  <property name="war" location="war"/>
  <property name="war.WEB-INF" location="war/WEB-INF"/>
  <property name="war.classes" location="war/WEB-INF/classes"/>
  <property name="war.lib" location="war/WEB-INF/lib"/>

  <target name="clean">
    <delete dir="${dist}"/>
    <delete dir="${war}"/>
  </target>

  <target name="compile">
    <mkdir dir="${war.classes}" />
    <mkdir dir="${war.lib}" />

	<!-- For GAE. Evidently, this makes our version dependencies explicit. -->
    <copy todir="${war.lib}" flatten="true">
      <fileset dir="appengine-java-sdk/lib/user">
        <include name="**/*.jar" />
      </fileset>
    </copy>

    <copy todir="${war.lib}" flatten="true">
      <fileset dir="lib">
        <include name="scala/scala-library.jar" />
        <include name="commons-codec-1.4.jar" />
      </fileset>
    </copy>

    <copy todir="${war.classes}">
      <fileset dir="src/resources">
        <exclude name="**/WEB-INF/**" />
      </fileset>
    </copy>

    <copy todir="${war.WEB-INF}">
      <fileset dir="src/resources/WEB-INF"/>
    </copy>

    <javac
        srcdir="src/java"
        destdir="${war.classes}"
        classpathref="project.classpath"
        debug="on" />

    <scalac srcdir="src/scala"
            destdir="${war.classes}"
            classpathref="project.classpath"
			deprecation="on" />
  </target>

  <target name="jar" depends="compile">
    <mkdir dir="${dist}" />
    <jar destfile="${dist}/${ant.project.name}.jar"
         basedir="${war.classes}" />    
  </target>
</project>