/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;
import java.time.format.DateTimeFormatter;
import java.time.LocalDate;
import java.time.format.DateTimeParseException;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		System.out.println("Esta data é válida! " + new DateValidator().isValid("10/12/2017"));
		System.out.println("Esta data é inválida! " + new DateValidator().isValid("10122017"));
	}
}

    class DateValidator {
       
       public boolean isValid(String date) {
       	  try {
             DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy");
             LocalDate d = LocalDate.parse(date,formatter);	
             return true;
       	  } catch (DateTimeParseException e) {
       	  	return false;
       	  }   
       }
    }