Add custom validation via annotation to graphQL java

Question

From the blogs online I understood.

By default, standard GraphQL types (String, Integer, Long, Float, Boolean, Enum, List) will be inferred from Java types. Also, it will respect @javax.validation.constraints.NotNull annotation with respect to value's nullability, as well as @GraphQLNonNull

I am trying for an annotation @UUID which could validate

@Target(ElementType.FIELD)
@Constraint(validatedBy={})
@Retention(RUNTIME)
@Pattern(regexp="^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$")
public @interface UUID {
    String message() default "{invalid.uuid}";
    Class<?>[] groups() default {};
    Class<? extends Payload>[] payload() default {};
}

public class Post {

    public Post() {
    }

    private String id;
    private String title;
    @UUID
    private String category;
    private Author author;

}

The annotation is not working while I am trying to add a post with the mutation. Please help with this.

Answer 1

There is no resolver here so I'm not sure how you create MutationResolver so I will put mu example and hope it helps.

Important is that you need to have @Validated and @Valid annotations.

So in my case: Schema:

schema {
    query: Query
    mutation: Mutation
}


type Vehicle {
    id: ID!
    name: String
}

input VehicleInput {
    name: String
    type: String
}

type Mutation {
    addVehicle(vehicle: VehicleInput): Vehicle
}

Resolver:

@Validated
@Component
@RequiredArgsConstructor
public class VehicleMutationResolver implements GraphQLMutationResolver {

    public Vehicle addVehicle(@Valid VehicleInput input) {
        return new Vehicle(UUID.randomUUID().toString(), input.getName());
    }
}

And input object:

@Data
@ToString
public class VehicleInput {

    private String type;

    @Size(min = 3)
    private String name;
}

So if you provide string that is smaller than 3 you will get error addVehicle.input.name: size must be between 3 and 2147483647

If this doesn't help please provide more data.