How can I iterate over properties from a file?

All my projects and their versions are defined in a properties file like this:

ProjectNameA=0.0.1
ProjectNameB=1.4.2

I'd like to iterate over all the projects, and use their names and versions in an Ant script.

At present I read the entire file using the property task, then iterate over a given list in a for loop like this:

<for list="ProjectNameA,ProjectNameB" param="project">
   <sequential>
    <echo message="@{project} has version ${@{project}}" />
   </sequential>
</for&开发者_运维知识库gt;

How can I avoid the hard-coding of the project names in the for loop? Basically iterate over each line and extract the name and the version of a project as I go.

Seeing as you're already using antcontrib for, how about making use of the propertyselector task:

<property file="properties.txt" prefix="projects."/>
<propertyselector property="projects" match="projects\.(.*)" select="\1"/>

<property file="properties.txt" />
<for list="${projects}" param="project">
    ...
</for>

The idea here is to read the properties once with the projects prefix, and use the resulting set of properties to build a comma-separated list of projects with the propertyselector task. Then the properties are re-read without the prefix, so that your for loop can proceed as before.

Something you want to keep in mind, if you are reading additional .property files (besides build.properties) is scoping. If you read an additional file (via the property file="foo.property") tag, ant will show that the file was read, and the properties loaded. However, when you goto reference them, they come up un-defined.