@Nonnull
public static File mergeFiles(@Nonnull File... files) {
if (files.length == 0) {
throw new IllegalArgumentException("no files to merge");
}
File result = ObjectUtils.clone(files[0]);
for (int index = 1; index < files.length; index++) {
mergeFiles(result, files[index]);
}
return result;
}
/** pre-condition: mergeTo and beMerged are isostructural */
private static void mergeDirectoryFiles(
@Nonnull DirectoryFile mergeTo, @Nonnull DirectoryFile beMerged) {
for (File file : beMerged.getChildren()) {
final File fileInMergeTo = findFirst(mergeTo.getChildren(), file, ISOSTRUCTURAL_FILE);
if (fileInMergeTo == null) {
mergeTo.addChild(ObjectUtils.clone(file));
} else {
mergeFiles0(fileInMergeTo, file);
}
}
}