How to add Ivy to Ant dynamically

Question

Typically, to make Ivy tasks available to an Ant build, you need to:

1. Add ivy.jar to ${ANT_HOME}/lib.
2. Add an xmlns:ivy="antlib:org.apache.ivy.ant" declaration to your build.xml's <project> element.
3. Add a <taskdef> declaration inside build.xml that reference's the ivy.jar's antlib.xml file where all other tasks are defined.

I'd like to accomplish all of the above except the first step (adding ivy.jar to ${ANT_HOME}/lib). I'd like to have ivy.jar living somewhere inside my project, say, at lib/buildtime/ivy.jar, and somehow reference lib/buildtime/ivy.jar as where Ivy is located.

Is this possible? If so, how? If not, why? Thanks in advance!

Answer 1

The taskdef (step 3) is not required if the ivy jar is located in a standard ANT library directory.

I would recommend including a special "bootstrap" target that will install the ivy jar. Once this is done all other dependencies (including 3rd party ANT tasks) can be downloaded by ivy as a build dependency.

Here is my default build file that demonstrates the concept:

<project name="demo" default="resolve" xmlns:ivy="antlib:org.apache.ivy.ant">

    <target name="bootstrap" description="Install ivy">
        <mkdir dir="${user.home}/.ant/lib"/>
        <get dest="${user.home}/.ant/lib/ivy.jar" src="http://search.maven.org/remotecontent?filepath=org/apache/ivy/ivy/2.3.0/ivy-2.3.0.jar"/>
    </target>

    <target name="resolve" description="Use ivy to resolve classpaths">
        <ivy:resolve/>

        <ivy:report todir='build/ivy-reports' graph='false' xml='false'/>

        <ivy:cachepath pathid="compile.path" conf="compile"/>
        <ivy:cachepath pathid="test.path"    conf="test"/>
    </target>

    <target name="clean" description="Cleanup build files">
        <delete dir="build"/>
    </target>

    <target name="clean-all" depends="clean" description="Additionally purge ivy cache">
        <ivy:cleancache/>
    </target>

</project>

Notes:

• The "bootstrap" target only needs to be run once on a new development environment. Once installed the ivy jar is available to all future ANT runs.
• This example doesn't use "$ANT_HOME/lib" (which you may not have write permissions for). Instead it uses the lesser known "$HOME/.ant/lib" directory which serves the same purpose.