//calculate our destination directory; it is either the destDir
//attribute, or the base dir of the fileset (for in situ updates)
File toDir = hasDestDir ? destDir : fr.getBaseDir();
//determine the destination filename via the mapper
String[] destFilenames = destMapper.mapFileName(fr.getName());
if (destFilenames == null || destFilenames.length != 1) {
//we only like simple mappers.
throw new BuildException(ERROR_BAD_MAP + fr.getFile());
}
File destFile = new File(toDir, destFilenames[0]);