自己想的一个java日期验证，不用正则

/**
     * <p>Checks if the field is a valid date.  The <code>Locale</code> is
     * used with <code>java.text.DateFormat</code>.  The setLenient method
     * is set to <code>false</code> for all.</p>
     *
     * @param value The value validation is being performed on.
     * @param locale The locale to use for the date format, defaults to the default
     * system default if null.
     * @return true if the date is valid.
     */
    public boolean isValid(String value, Locale locale) {

        if (value == null) {
            return false;
        }

        DateFormat formatter = null;
        if (locale != null) {
            formatter = DateFormat.getDateInstance(DateFormat.SHORT, locale);
        } else {
            formatter =
                    DateFormat.getDateInstance(
                            DateFormat.SHORT,
                            Locale.getDefault());
        }

        formatter.setLenient(false);

        try {
            formatter.parse(value);
        } catch(ParseException e) {
            return false;
        }

        return true;
    }