SimpleDateFormat parse(string str) doesn't throw an exception when str = 2011/12/12aaaaaaaaa?

Question

Here is an example:

public MyDate() throws ParseException {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/d");
    sdf.setLenient(false);
    String t1 = "2011/12/12aaa";
    System.out.println(sdf.parse(t1));
}

2011/12/12aaa is not a valid date string. However the function prints "Mon Dec 12 00:00:00 PST 2011" and ParseException isn't thrown.

Can anyone tell me how to let SimpleDateFormat treat "2011/12/12aaa" as an invalid date string and throw an exception?

Answer 1

Java 8 LocalDate may be used:

public static boolean isDate(String date) {
    try {
        LocalDate.parse(date, DateTimeFormatter.ofPattern("yyyy/MM/dd"));
        return true;
    } catch (DateTimeParseException e) {
        return false;
    }
}

If input argument is "2011/12/12aaaaaaaaa", output is false;

If input argument is "2011/12/12", output is true