jsr 303 validate a number and auto initialize to 0

Question

in my domain class I have an integer which is being populated from form. if user enters any digit , it will be validated and if he leaves the input box empty, it will default initialize to 0

so far I have done the first part with

@NumberFormat(style = Style.NUMBER)

How to go about default initilizing it to 0?

Answer 1

If youfr probldem is that the default value is 0 when the user does not enter anything in the box, set a validator for the accepted range, and initialize it to a number outside that range. If all numbers are acceptable, change it from an int to an Integer, and use @NotNull.

Answer 2

How about assigning the field an initial value?

If the field is of type int it automatically has a value of 0.

Answer 3

Just do:

validation rules
private int numberToValidate = 0;