Subversion is a popular version control software and replacement for CVS, the grand-daddy of all version control software which is still widely used in open source community.

Recently I had the necessity to invoke Subversion commands like checkout from Ant, a popular java based build software which replaces make tool.

There are two ant tasks to accomplish this, the better one is SvnAnt from Subclipse project. However configuring it to work was non-trivial as proper usage documentation was missing. So I decided simplify the process to make your life easier.

However the extensive commands it supports are well documented.
Note: If prompted for user name / password use guest / guest.

Why SvnAnt?
Subversion is a full-fledged version control software obviously supporting commands like checkout, add or commit. The ant task from O'Reily didn't even support checkout! It supported a very limited set from the available commands.
So I went for svnant task which had much better support. Also this way you don't have to mess with exec'ing the Subversion CLI commands directly from your ant script. It is wrapped up for ease of use. It can also use JNI interface for speed.

To provide access to the Subversion API, svnant uses either the javahl - Subversion Java bindings or Subversion's command line programs (which must be installed and in your PATH).

javahl uses JNI which must be setup appropriately. I preferred using the Subversion's command line programs as subversion was already installed in my system.

Steps:
1. I am assuming you already have ant installed. If not do it first. Ensure %ANT_HOME% ($ANT_HOME for *nix) is defined and %ANT_HOME%\bin is appended to your %PATH%.

2. If you do not have subversion installed then first download it and install.

2.1 Ensure that svn is in your path by invoking svn from a command windows (cmd for windows, bash etc. for *nix).

3. Download svnant and extract the files to any directory.

4. Go to your project directory. If it doesn't have a lib (or equivalent) directory to store required jar files then create one and copy all the files (*.jar ) from svnant's lib directory:
commons-lang-2.0.jar
jakarta-regexp-1.3.jar
svnClientAdapter.jar
svnant.jar
svnjavahl.jar

5. To use svn task you have to add a taskdef to your build file. Use either of the following:
Option 1:

This requires the lib directory to be included with either "ant -lib lib" or by adding an extra parameter:

where project.classpath is previously defined as:

Option 2 is simpler:

The project.classpath is previously defined as shown before.

For example you can use this simple build.xml file to fetch latest code from WordPress repository:

Run this script by simply typing ant.

BTW: I think Subversion as version control software and ant as build and deployment software are two very strong products which should be part of any enterprise open source software stack.