import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.util.Locale;

public class Main {
    public static void main(String[] args) {
        String strDate = "31/05/2011";
        DateTimeFormatter dtf = DateTimeFormatter.ofPattern("dd/MM/uuuu", Locale.ENGLISH);
        LocalDate date = LocalDate.parse(strDate, dtf);
        System.out.printf("Default format: %s, Custom format: %s%n", date, date.format(dtf));
    }
}