Bytebuddy loaded class not found - byte-buddy

Question

I am trying to build a class that holds a reference to another class object through a field. Something like this:
Class A extends Parent {private B b;}
Class B extends Child {private String s;}
I am able to make and load Class B first, instantiate its object and set it to the field in class A by intercepting A's constructor.
However, when I try to load the unloaded type A it throws class not found exception for type B even though its already loaded.
I hope this is possible to do with bytebuddy. If yes, what am I doing wrong?
Here is the implementation:
private static final ClassLoader SYSTEM_CLASS_LOADER = ClassLoader.getSystemClassLoader();
public Class<? extends Parent> generateParentClass(ParentConfig config) throws Exception {
Map<String, Class<? extends Child>> fieldMap = config.getChildren().stream().collect(Collectors.toMap(ChildConfig::getName, this::generateChildClass));
Implementation.Composable constructorInterceptor = MethodCall.invoke(Parent.class.getConstructor());
for(Map.Entry<String, Class<? extends Child>> entry : fieldMap.entrySet()) {
Child child = entry.getValue().getDeclaredConstructor().newInstance();
constructorInterceptor = constructorInterceptor.andThen(FieldAccessor.ofField(entry.getKey()).setsReference(child));
}
DynamicType.Builder<Parent> typeBuilder = new ByteBuddy()
.subclass(Parent.class)
.name(Parent.class.getPackageName() + "." + config.getType())
.annotateType(Parent.class.getAnnotations())
.constructor(any())
.intercept(constructorInterceptor);
for(Map.Entry<String, Class<? extends Child>> entry : fieldMap.entrySet())
typeBuilder = typeBuilder.defineField(entry.getKey(), entry.getValue(), Modifier.PRIVATE);
DynamicType.Unloaded<Parent> unloadedType = typeBuilder.make();
return unloadedType.load(SYSTEM_CLASS_LOADER).getLoaded(); //ClassNotFoundException for Type Child
}
private Class<? extends Child> generateChildClass(ChildConfig config) {
DynamicType.Builder<Child> typeBuilder = new ByteBuddy()
.subclass(Child.class)
.name(Child.class.getPackageName() + "." + config.getName())
.annotateType(Child.class.getAnnotations());
for(Attribute attribute : config.getAttributes())
typeBuilder = typeBuilder.defineField(attribute.getName(), attribute.getTypeClass(), Modifier.PRIVATE);
DynamicType.Unloaded<Child> unloadedType = typeBuilder.make();
return unloadedType.load(SYSTEM_CLASS_LOADER).getLoaded();
}

Answer 1

Whenever you run unloadedType.load(SYSTEM_CLASS_LOADER), you create a new class loader. All types that are loaded within this class loader are not visible to other classes outside of it. What you can do is to merge two unloadedType values and load them together into the same class loader. Types are still available via TypeDescriptions. Alternatively, you can define a custom ClassLoadingStrategy or use a default strategy that uses injection via unsafe or via a method handle lookup (Java 9+). The load method accepts it as its second argument.