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In my continuing quest into all that is good with Ant, one of my tasks was to interface with our Subversion repository in order to export the latest code base, possibly tag it, al before shipping it off to the testing or production server.  In looking around, there are several ways to doing this – some that are limited to use within Eclipse, some that require third party downloads, and several others that were not documented well enough to know what they did.  In the end, I chose to use SVNAnt and configure things in a manner that I could run the build file from within Eclipse or from the command line if the need arose.

What is SVNAnt?

According to the documentation, SVNAnt "… is an ant task that provides an interface to Subversion revision control systems …"  Once SVNAnt is configured in your Ant build file, you can do almost anything via your build file that you could do using a Subversion client.  There are a few commands that are not supported, but there are 23 that are including the most common add, commit, export, etc. commands that you typically use.

You can download SVNAnt from http://subclipse.tigris.org/svnant.html.  The current release at this point is 1.0.0 which is available via a zip file.  In all of my incantations trying different things, I actually pulled the latest release from the SVN repository and compiled it to give me a 1.1.0 release.  This is the release I will be setting up below.

Setting it Up

1. Download the latest release of SVNAnt from the SVN repository at: http://subclipse.tigris.org/svn/subclipse/trunk/svnant/
2. Next, go to the folder in which you downloaded SVNAnt and copy the build.properties.example file to build.properties.  Uncomment all of the property lines and then add a single line at the bottom with the following text.

   targetJvm = 1.6

   In my case, I am running JVM 1.6.X with ColdFusion 8.  If you are running a lower JVM, adjust this number to match your JVM.  Then, save the file.

3. Next, assuming you already have Ant installed (see http://www.alagad.com/go/blog-entry/better-development-practices-with-ant if not ), at the command line move to the folder where you downloaded SVNAnt above and type:

   ant makeDistrib

   You should get a bunch of stuff displayed with the last thing being a build successful message.   You should now have version 1.1.0 compiled and ready to go.

4. Now, inside of your SVNAnt folder should be a folder called build, in which should reside a zip file named svnant-1.1.0.zip.  If you open up that zip file, in it should be a folder called lib, in which should be a collection of jar files.  These are the important ones that we need.  Extract / copy all of these files to the lib folder under your Ant installation.  In my case, I am using the Ant installation that comes as part of Eclipse, so I copied the files to:

   C:eclipsepluginsorg.apache.ant_1.7.0.v200706080842lib

With that complete, SVNAnt should be setup and we are ready to start writing build files.

A Test Build

I am not going to get into how to write a build file here, but lets at least create one that will test our SVNAnt installation.  Create a file called build.xml somewhere in your file system and put the following XML in it.

<project name="test" default="svn.test" basedir=".">
     <path id="svnant.classpath"  >
        <fileset dir=" [ PATH TO ANT LIB FOLDER WHERE SVNANT JAR FILES WERE PUT ] " >
            <include name="*.jar" />
        </fileset>
    </path>

    <typedef resource="org/tigris/subversion/svnant/svnantlib.xml" classpathref="svnant.classpath" />

    <target name="svn.test">
        <svn>
            <wcVersion path=" [ PATH TO CHECKED OUT SVNANT WORKING COPY ] " />
        </svn>
        <echo message= "Subversion repository url: ${repository.url}" />
    </target>
</project>

Lets break this down to see what is happening here.  The path tag tells the build file where to find SVNAnt.  The only thing you will need to change here is the path to the Ant lib folder where you put the SVNAnt jar files.  Note: for windows, the path needs to contain forward double slashes, so "c:eclipse" would be "c:eclipse".

After the path tag, is the typedef tag.  The typedef tag defines the svn type so that we can use it later on.  Everything here should work as is with no changes.

Last we get to our target.  The target is the portion of the build file that will execute the various tasks you want.  In this case, we are doing a simple wcVersion SVN command to get some information about a subversion repository.  If you replace the contents of the path attribute with the file path to the working copy of the SVNAnt repository you checked out earlier, you should be able to run the build file.  Again, note for windows, the path needs to contain forward double slashes, so "c:eclipse" would be "c:eclipse".

Now, if you run this within Eclipse or run it from the command line, you should get back a nice little Build Successful message.  You now have the ability to perform Subversion operations from Ant and make your deployment process so much easier.

Learn More

To learn more about the commands that are available via SVNAnt, check out the documentation page for SVNAnt at http://subclipse.tigris.org/svnant/svn.html.