java.lang.NoSuchMethodError:
org.apache.tools.ant.util.FileUtils.getFileUtils()L
org/apache/tools/ant/util/FileUtils;
was thrown when i use <fileset> even the simple build.xml below:

<project name="tmp" default="cp">
   <target name="init">
    <delete dir="test1"/>
    <delete dir="test2"/>
    <mkdir dir="test1"/>
    <mkdir dir="test2"/>
   </target>

   <target name="cp" depends="init">

    <copy todir="test2">
       <fileset dir="test1">
       </fileset>
    </copy>
   </target>
</project>

Can anyone tell me Y???