Java Programs easy way

package New;

import java.util.StringTokenizer;

public class Prog1 {

      static int op;

      public static void abc(String s) {

            StringTokenizer st2 = new StringTokenizer(s, "/");

            String d = st2.nextToken();

            String m = st2.nextToken();

            String y = st2.nextToken();

            if ((Integer.parseInt(d) <= 31) && (Integer.parseInt(d) >= 1)

            && (Integer.parseInt(m) >= 1) && (Integer.parseInt(m) <= 12)

            && y.length() == 4 && d.length() == 2 && m.length() == 2)

                  op = 1;

            else

                  op = 0;

      }

      public static void main(String[] args) {

            String d = "12/06/1987";

            abc(d);

            System.out.println(op);

      }

}