apache ant mutable file type property

Question

I'm looking for a way to load properties from a file in ant script. Specifically, I want to loop through a list of properties files, and on each loop load the properties from the current file and do something with it. Something like this:

<for param="file">
  <path>
    <fileset containing my properties files.../>
  </path>
  <sequential>
     <property file="@{file}" prefix="fromFile"/>
     <echo message="current file: @{file}"/>
     <echo message="property1 from file: ${fromFile.property1}"/>
  </sequential>
</for>

The code above results in only the first properties file from being read, even though each loop does go through each properties file name. I know property is immutable, and I can get around it by using local task or variable task from ant-contrib. However, I don't know how to apply them here, or if they even contribute to a solution in this case.

Answer 1

Here I used Antcontrib and two property files in the same directory as the build.xml .

p1.properties:

property1=from p1

p2.properties:

property1=from p2

The trick is to use antcall inside the for loop to call another target. Properties set in the called target at not propagated back to the caller.

build.xml:

<project name="test" default="read.property.files">
  <taskdef resource="net/sf/antcontrib/antcontrib.properties">
    <classpath>
      <pathelement location="ant-contrib/ant-contrib-1.0b3.jar"/>
    </classpath>
  </taskdef>

  <target name="read.property.files">
    <for param="file">
      <path>
        <fileset dir="." includes="*.properties"/>
      </path>
      <sequential>
        <antcall target="read.one.property.file">
          <param name="propfile" value="@{file}"/>
        </antcall>
      </sequential>
    </for>
  </target>

  <target name="read.one.property.file">
    <property file="${propfile}" />
    <echo message="current file: ${propfile}" />
    <echo message="property1 from file: ${property1}"/>
  </target>
</project>

The output is:

Buildfile: /home/vanje/anttest/build.xml

read.property.files:

read.one.property.file:
     [echo] current file: /home/vanje/anttest/p1.properties
     [echo] property1 from file: from p1

read.one.property.file:
     [echo] current file: /home/vanje/anttest/p2.properties
     [echo] property1 from file: from p2

BUILD SUCCESSFUL
Total time: 0 seconds

Answer 2

In my original question I had trouble loading entire properties file from within for loop (from ant-contrib). Turns out inside for loops, ant-contrib's own var task works just the same as property task from pure ant. All I have to do is replace <property file="@{file}" prefix="fromFile"/> with <var file="@{file}"/> . The properties loaded will be overwritten with the latest values and I don't even need prefix attribute to keep track of which loop I'm currently on.