Set deserializing in Spring Native image problem - jackson-databind

Question

I'm stuck with a problem on a built Spring Native image:
Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.http.converter.HttpMessageConversionException: Type definition error: [collection type; class java.util.HashSet, contains [simple type, class java.lang.Object]]; nested exception is com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of java.util.HashSet (no Creators, like default constructor, exist): no default no-arguments constructor found
at [Source: (org.springframework.util.StreamUtils$NonClosingInputStream); line: 5, column: 14] (through reference chain: com.example.app.payload.request.SignupRequest["roles"])] with root cause
From this description it seems that I need use custom deserializer, but the problem appears only if I run code from native image - same code works perfectly well if run from JAR.
POJOs are very simple:
public class SignupRequest {
#NotBlank
#Size(min = 3, max = 20)
private String username;
#NotBlank
#Size(max = 50)
#Email
private String email;
private Set<String> roles;
#NotBlank
#Size(min = 6, max = 40)
private String password;
// getters & setters no Lombok (but Lombok is in project)
}
Controller uses standard (nothing fancy) annotations:
public ResponseEntity<MessageResponse> registerUser(#Valid #RequestBody SignupRequest signUpRequest)
Has anyone encountered a similar problem?

Answer 1

Finally I found missing part - I have to add HashSet to SerializationHint:
#SpringBootApplication
#SerializationHint(types = {
java.util.HashSet.class
})
public class SpringNativeApplication {
public static void main(String[] args) {
// ...
}
}