Java program expecting input doesn't work when running from Ant?

Question

So I have a simple java program that prints a message and asks for user input. The program runs fine, until I try to run it through ant.

When I use the below build file, the program never prints the message.

When I run with ant -verbose, it says that "The ' characters around the executable and the arguments are not part of the command"

What am I doing wrong in the build file? I'm confused because this build file works fine for programs that don't ask for user input.

<project name="lab4" default="run" basedir=".">

    <property name="src" value="."/> 

    <target name="clean">
       <delete>
              <fileset dir="${src}" includes="**/*.class,META-INF,*/**.jar"/>
           </delete>
    </target>

    <target name="compile" depends="clean">
        <javac srcdir="${src}" destdir="${src}" includes="**/*.java"  includeantruntime="false"/>
    </target>

    <target name="run" depends="compile">
      <java classpath="${src}" classname="CountLetters1" failonerror="yes"/>
    </target>

</project>

Answer 1

Summarizing the "solution" from the comments to the question:

The problem here appears to be that the program does not include a line break in its input prompt. This causes Ant to not show the prompt (it's waiting for the newline).

Other than that, the example is actually running fine.