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

public class Main {
	public static void main(String[] args) {
		String[] arr = { "2015-02-02", "2015-02-02 23:23:23" };
		DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuu-MM-dd", Locale.ENGLISH);

		for (String s : arr) {
			ParsePosition pp = new ParsePosition(0);
			LocalDate.from(dtf.parse(s, pp));
			if (pp.getIndex() < s.length()) {
				System.out.println("'" + s + "' is not a date string as per the specified date pattern.");
			}
		}
	}
}