java -Djarmode=layertools -jar fat.jar list

FROM .../openjdk-alpine:11 as builder
WORKDIR application
COPY fat.jar fat.jar
RUN java -Djarmode=layertools -jar fat.jar extract
...
FROM ...openjdk-alpine:11
WORKDIR application
COPY --from=builder application/dependencies/ ./
COPY --from=builder application/spring-boot-loader/ ./
...
ENTRYPOINT ["java", "org.springframework.boot.loader.JarLauncher"]

DB db = DBMaker.fileDB("/some/file").encryptionEnable("password").make();
ConcurrentNavigatableMap<Integer, String> map = db.treeMap(...);

class LegacyBeanDefinitionRegistrar implements ImportBeanDefinitionRegistrar {
// ...
registerBeanDefinition() {
      Reflections scanner = new Reflections("com.legacy.package");
      Set<Class<?>> classes = scanner.getTypesAnnotatedWith(LegacySingleton.class);
      for(Class<?> aClass : classes) {
        GenericBeanDefinition bd = new GenericBeanDefinition();
        bd.setBeanClass(aClass);
        // bd.addQualifier(new AutowireCandidateQualifier(Legacy.class)); // можно добавлять свои квалифаеры
        beanDefinition.setScope(beanDefinition.SCOPE_SINGLETON); // например
        registry.registerBeanDefinition(Introspector.decapitalize(aClass.getSimpleName()), bd);
      }
}
}

@Autowired private Map<String, Handler> map; // key = bean id, Handler - @Bean

interface HandlerInterface { String myType(); void doWork(); }
/// --
public class Controller {
  private Map<String, Handler> map;
  public Controller()(List<HandlerInterface> somethings) {
    map = somethings.stream.collect(toMap(SomethingInterface::myType), Function.identity());
  }
  // ...
}

@Autowired default void regMe(Controller c) {
  c.register(this.getType, this);
}