Question

In Java 7 with the new I/O APIs, is there an easy way to list a directory’s content by last modified date? Basically I only need to get the file the wasn’t modified for the longest time (sort by last modified ascending, take first filename).

Answer 1

There’s no real “easy way” to do it, but it is possible:

List<Path> files = new ArrayList<>();
try(DirectoryStream<Path> stream = Files.newDirectoryStream(dir)) {
    for(Path p : stream) {
        files.add(p);
    }
}

Collections.sort(files, new Comparator<Path>() {
    public int compare(Path o1, Path o2) {
        try {
            return Files.getLastModifiedTime(o1).compareTo(Files.getLastModifiedTime(o2));
        } catch (IOException e) {
            // handle exception
        }
    }
});

This will sort the files soonest modified files last. DirectoryStreams do not iterate through subdirectories.