Ant+Junit works on first run and never again

Hey guys I've been trying all day to get an ant file to automatically build my project. The file (appended below) was on a web page I found and is pretty thorough.

My problem is that it works as long as I don't run the "clean" target. Once the I run the "clean" target the "test" target ceases to work. I get NoClassFound errors on all test classes. Even though it worked earlier.

I'm working on a Macbook (10.5.8) using the latest version of eclipse. This error occurs running the file from eclipse and from a terminal using Ant version 1.7.1

I modified the file slightly to adapt it to my file structure which is as follows:

src/
   packageA.packageB/
                     ClassA.java
                     ...
                     ClassN.java

unittests/
          packageA.packageB/
                            AllClassTests.java
                            ClassATest.java
                            ...
                            ClassNTest.java

lib/
    junit-4.7.jar

The ant file is:

<project name="SampleJUnitTests" default="dist" basedir=".">
<description>
    DataTypes Build File
</description>
<!-- set global properties for this build -->

<property name="project_name" value="DataTypes"/>
<property name="src" location="src"/>
<property name="build" location="bin"/>
<property name="dist"  location="dist"/>
<property name="lib"  location="lib"/>
<property name="reports" location="reports"/>
<property name="tests" location="unittests"/>
<property name="tmp" location="tmp_file"/>

<!-- the names of various distributable files -->
<property name="jar_name" value="${project_name}.jar"/>
<property name="war_name" value="${project_name}.war"/>

<!-- top level targets -->

<target name="compile" depends="init" description="compile the source code " >
    <javac srcdir="${src}" destdir="${build}">
        <classpath>
            <fileset dir="lib">
                <include name="**/*.jar"/>
            </fileset>
        </classpath>
    </javac>
</target>

<target name="dist" depends="compile" description="generate the distributable files " >
    <!-- Put everything in ${build} into the MyProject-${DSTAMP}.jar file -->
    <jar jarfile="${dist}/${jar_name}" basedir="${build}"/>
</target>

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

<target name="run-tests" depends="compile" description="run your test suite" >
    <junit printsummary="yes" haltonfailure="no" showoutput="yes" tempdir="${tmp}">
        <classpath>
            <pathelement path="${build}"/>
            <fileset dir="lib">
                <include name="**/*.jar"/>
            </fileset>
        </classpath>
      <batchtest fork="yes" todir="${reports}/raw/">
        <formatter type="xml"/>
        <fileset dir="${tests}">
          <include name="**/*.java"/>
          <exclude name="**/All*Tests.java"/>
        </fileset>
      </batchtest>
    </junit>
</target>

<target name ="test" depends="run-tests">
    <junitreport todir="${reports}">
      <fileset dir="${reports}/raw/">
        <include name="TEST-*.xml"/>
      </fileset>
      <report format="frames" todir="${reports}\html\"/>
    </junitreport>
</target>

<target name ="run" depends="" description="if this project can be run, run it" >
</target>

<!-- supporting targets -->

<target name="init" description="initialize the build environment" >
    <!-- Create the time 开发者_JS百科stamp -->
    <tstamp/>
    <!-- Create directory structures -->
    <mkdir dir="${build}"/>
    <mkdir dir="${lib}"/>
    <mkdir dir="${dist}/lib"/>
    <mkdir dir="${reports}"/>
    <mkdir dir="${reports}/raw/"/>
    <mkdir dir="${reports}/html/"/>
    <mkdir dir="${tmp}"/>
</target>

<target name="all" depends="clean, test">
</target>

I give up and hope that someone can shine a light on my problem. Thanks a lot!

You haven't got any Ant target which builds the test classes. You could do this as part of the compile target if you wanted:

<target name="compile" depends="init" description="compile the source code " >
  <javac srcdir="${src}" destdir="${build}">
    <classpath>
      <fileset dir="lib">
        <include name="**/*.jar"/>
      </fileset>
    </classpath>
  </javac>
  <javac srcdir="${tests}" destdir="${build}">
    <classpath>
      <pathelement path="${build}"/>
      <fileset dir="lib">
        <include name="**/*.jar"/>
      </fileset>
    </classpath>
  </javac>
</target>