Using Properties Class with Map within an spring native build

Question

I try to build a native executable with GraalVM and Spring Boot 3.0.

When I use configuration properties class including a HashMap, starting of these application fails.

example project

This class contains a simple map:

@Validated
@Data
@Component
@ConfigurationProperties(prefix = "test-props")
@FieldDefaults(level = AccessLevel.PRIVATE)
public class TestProperties {

    @NotEmpty
    HashMap<String, PermissionsConfig> datagroups;

    @Data
    @Builder
    @AllArgsConstructor
    @NoArgsConstructor
    @FieldDefaults(level = AccessLevel.PRIVATE)
    public static class PermissionsConfig {
      // fields
    }
}

With configuration:

test-props:
  datagroups:
    data:
      read:
        code: READ_DATA
        urlPattern:
          - /some/pattern/

With this small test runner:

@Slf4j
@Component
@RequiredArgsConstructor
@FieldDefaults(makeFinal = true, level = AccessLevel.PRIVATE)
public class TestRunner implements ApplicationRunner {

    TestProperties testProperties;

    @Override
    public void run(ApplicationArguments args) throws Exception {

        if (testProperties.getDatagroups() == null) {
            throw new RuntimeException("property not binded");
        }

        log.info("property {}", testProperties);

    }
}

Starting this as "normal" java application, everything works fine. As soon as I build the native executable I get following issue:

***************************
APPLICATION FAILED TO START
***************************

Description:

Binding to target org.springframework.boot.context.properties.bind.BindException: Failed to bind properties under 'test-props' to test.properties.TestProperties failed:
    Property: test-props.datagroups
    Value: "null"

I also tried to add additional hints for the property class. Before adding these hints the validation didn't work at all.

I would expect that this would also work within a native image.

What have I overseen?

Steps to reproduce:

• get repo: https://github.com/sogmemu/HashMapInNativeBuild
• ./gradlew nativeCompile
• ./build/native/nativeCompile/app

Answer 1

I solved the issue for me. It is not Lombok or all the annotations. I removed it (but testet it also with all the annotations). In my example the AOT Compiler can not detect the subclasses used within the Map. Adding all of these sub classes as hints make it work.

public class TestHints implements RuntimeHintsRegistrar {
    @Override
    public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
        addAll(hints, TestProperties.class);
        addAll(hints, TestProperties.PermissionsConfig.class);
        addAll(hints, TestProperties.Permission.class);

    }
 }

See also issue on spring boot project

Update:

Instead of adding the hints It will also work to use @NestedConfigurationProperty to the Permission read and Permission history fields.

Since the Permission object was not defined within PermissionConfig it is a nested Object. Moving the class definition inside PermissionConfig class would also work