I was reading this article about new features in Eclipse 3.1. One feature mentioned that caught my eye was the ability to set a project based on an existing ANT build file, and the ability to export a project settings to an ANT build file. Unfortunately the article didn't explain how to do this import/export. I searched Eclipse's help, to no avail. After some messing around with eclipse I found out how to do it.

To export your project settings to an ANT build file:

1. In your navigator window, look for a file called ".project"
2. Right click on the file and click on "export"
3. On the window that pops up, select "Ant Buildfiles" and click on "next"
4. Select the appropriate project to use to generate the ANT buildfile
5. Click "finish"

You should now have two new build files on your project, "build.xml" and build-user.xml.

Any custom targets you create should go on build-user.xml, since build.xml will be overwritten every time a build file is generated.

To create a project from an existing ANT buildfile:

1. Click on File->New->Project
2. Select "Java Project from existing Ant Buildfile" and click "next"
3. Enter a project name, and select the build file to use to create the project
4. Select the javac declaration to be used to define the project
5. Click finish

I hope these instructions are helpful to others out there.