Does the following validation mean that the field cannot be null? ( @Size annotation )

Question

I have the following property in my Spring MVC Form bean using the javax.validation.constraints to validate the form bean as follows:

public class MyForm {     @Size(min = 2, max = 50)     private String postcode;      // getter and setter for postcode. } 

My question is: Does the @Size(min = 2) mean that the property cannot be null as it will always require a length greater than 2. The reason why I say that is because there is a @NotNull constraint in the same package and therefore does that make the @NotNull constraint redundant if I should use it in the above bean.

Answer 1

If you look at the documentation of the annotation Size (http://docs.oracle.com/javaee/6/api/javax/validation/constraints/Size.html)

You can read "null elements are considered valid."
Therefore you need to specify @NotNull on the top of your field.
You have two alternatives:

@NotNull  @Size(min = 2, max = 50) private Integer age; 

Or like Riccardo F. suggested:

@NotNull @Min(13) @Max(110) private Integer age;