Question

Hello
I am not able to get the correct validation.I think there is some error in this code so can anyone please help me solving this problem.

 public static boolean validateFee(String value) {

        boolean isvalid = true;
        try {
            int fee = 0;
            if (value != null && !value.isEmpty()) {
                fee = Integer.parseInt(value);
            }
        } catch (NumberFormatException ne) {
            // ne.printStackTrace();
            isvalid = false;
            return isvalid;

        }
        return isvalid;
    }
}

I am actaully using this code for validation of fee in which i m using a regex as [0-9]+.
This code i m using it in a common function.Actually validation call is done in the servlet as follows:

private Boolean validateFee(HttpSession session, PropertiesHandler props, String number) {
    Boolean isvalid = true;
    HashMap hashMap = new LinkedHashMap();
    number = ApplicationConstants.FEE_PATTERN;
    if (!Validation.validateFee(number)) {
        isvalid = false;
        hashMap.put("time", props.getText("error.fee.invalid.type"));
    }
    session.setAttribute("errorMessage", hashMap);
    System.out.println("Map size " + hashMap.size());
    logger.info("Exit validateTIme"); return isvalid;
} 

I think there is no error in that but i have a doubt in this function.I am facing a problem like if i give number to the fee also its taking validation.please help me out

Answer 1

Currently it allows value of null or “” to count as being valid – is that deliberate?

Note that your current code can be rewritten more simply:

public static boolean validateFee(String value) {
    try {
        if (value != null && !value.isEmpty()) {
            Integer.parseInt(value);
        }
        return true;
    } catch (NumberFormatException ne) {
        return false;
    }
}

Now if you want null/empty to count as invalid, I’d rewrite it as:

public static boolean validateFee(String value) {
    if (value == null || value.isEmpty()) {
        return false;
    }
    try {
        Integer.parseInt(value);
        return true;
    } catch (NumberFormatException ne) {
        return false;
    }
}