/**
 * javac -encoding utf-8 TestFileTime.java
 *
 * java -cp . TestFileTime2
 */
import java.util.Date;
import java.nio.file.Path;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.attribute.FileTime;
import java.text.SimpleDateFormat;
import java.io.Writer;

public class TestFileTime2 {
    public static void main(String[] args) {
        SimpleDateFormat ymd = new SimpleDateFormat("yyyyMMdd");
        String today = ymd.format(new Date());
        Path path = Paths.get(String.format("%s.txt", today));
        try (Writer w = Files.newBufferedWriter(path)) {
            w.write(today);
            w.write("\n");
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
        try {
            FileTime fileTime = FileTime.fromMillis(ymd.parse(today).getTime());
            Files.setLastModifiedTime(path, fileTime);
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        }
    }
}