Ant buildfiles are just text files, so the most straightforward way to create an Ant buildfile in Eclipse is:
As long as the file has a .xml extension, Eclipse will consider it to be a possible Ant buildfile, and will enable Ant-related actions when it is selected.
As will be demonstrated in a later section, an Ant buildfile can be created for an Eclipse plug-in that contains predefined targets related useful for deploying the plug-in.