Java annotation for Null but neither Empty nor Blank

Question

Is there are any java annotation(s) that can validate like the example below?

String test;
test = null; //valid
test = ""; //invalid
test = " &         


        

Answer 1

Did you try Hibernate-Validator? I think that's what you are looking for.

import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.NotBlank;
import org.hibernate.validator.constraints.NotEmpty;

public class MyModel  {

    @NotNull
    private String  str1;

    @NotEmpty
    private String  str2;

    @NotBlank
    private String  str3;

}