Amount validation - regular expression in Java

Question

In java class I need regular expression for amount validation with the following conditions:

1. Maximum price is 9999.99
2. Minimum amount is 1
3. Decimal values is optional (Paise is optional) that is 9999 is Valid

I write the following regular expression but it always return false for both valid and invalid inputs.

Here's example:

private static final String PRICE_PATTERN = "((/d{1,4})(((//.)(/d{0,2})){0,1}))";

public PriceCheck() {
    pattern = Pattern.compile(PRICE_PATTERN);
}

public boolean validate(final String username) {
    matcher = pattern.matcher(username);
    return matcher.matches();  // always return false;
}

Answer 1

请改用以下表达式：

private static final String PRICE_PATTERN = "((\\d{1,4})(((\\.)(\\d{0,2})){0,1}))";