I have a value in a properties file that I want to increment while the build is running. The goal is to copy a set of files and append a number to the front of each in order to maintain the order in which they were copied into the directory. I am using the <propertyfile> task as follows:

<propertyfile file="jsfiles.properties">
    <entry  key="file.number" type="int" operation="=" value="10" />
    <entry  key="file.number" type="int" default="010" operation="+" value="10" pattern="000" />
</propertyfile>

Then I do the copy:

<copy todir="${js-in.dir}">
    <resources>
        ...
    </resources>
    <chainedmapper>
        <flattenmapper />
        <globmapper from="*.js" to="${file.number}-*.js"/>
    </chainedmapper>
</copy>

This does exactly what I need it to EXCEPT that instead of the following output:

• 010-file1.js
• 020-file2.js
• 030-file3.js
• ...

I get:

• ${file.number}-file1.js
• ${file.number}-file2.js
• ${file.number}-file3.js
• ...

What am I doing wrong?