Use another object field value in spring message interpolation

Question

I am trying, if it's possible, to customize a message of a constraint with a value that is not actually the one that is being validated but belong to the same class.

public Car {
  @NotEmpty(message = The car of the model '${this.model}' requires a plate_number)
  String plate_number;

  String model;
}

And now after creating a new instance of it

Car myCar = new Car(null, Audi);

and having validated, I want to get the message "The car of the model Audi requires a plate_number"

I do not know if its possible. Thanks :)

Answer 1

I dont know about @NotEmpty annotation because your are creating a Car object using constructor and I also know when using javax or jakarta validation usually it is on DTO exposed into REST endpoints.

As a alternative you can using Assert.notNull into contructor:

public class Car {

  private String model;

  private String plate_number;


  public Car(String model, String plate_number) {
    this.model = model;
    Assert.notNull(plate_number,
        "The car of the model " + this.model + " requires a plate_number");
    this.plate_number = plate_number;
  }
}

And now when you will pass:

Car car = new Car("Audi", null);

In console you will have next one error message:

java.lang.IllegalArgumentException: The car of the model Audi  requires a plate_number