原始布尔值的 javax.validation.constraints？

Question

Small question on javax.validation.constraints and how to validate the primitive boolean (not Boolean)

Currently, I am using @Min(1), @Size(min = 1, max = 10), @NotBlank, etc, to validate my primitive int, and String object. It is doing the job fine, very happy.

How to validate the same for a primitive boolean please? Meaning, I have a boolean that I would like to be a must input in the JSON request.

I understand if I do Boolean, I can combine it wit some kind of @NotNull validation. How to do the same with the primitive boolean please?

I would like the client to must input this field. And the value of the field must be either true or false.

I do not want to default it to false or true if the field is not present.

This is a valid example

{
    "field": false
}

Here, there is a typo in the field, hence, the field field is not present, it is not valid.

{
    "fielddwdw": false
}

Here, the value of the field is "true", the string, hence invalid.

{
    "field": "true"
}

Here, the value is neither true or false, invalid

{
    "field": foo
}

I was hoping for some kind of

    @MagicalBooleanValidationAnnoation
    private boolean field;

But just would like to achieve this use case.

Thank you

Answer 1

You can't do the same as a Boolean with @NotNull annotation for a primitive boolean , because the primitive boolean has only 2 possible values, and none of them represent the lack of a value.

If you want a 3-state value, with states true , false , and missing , you must use Boolean .

Or you can use an enum with 3 values.