How to use java reflection to return a Collection that contains something other then Objects

So my problem is that im currently trying to use java's reflection to traverse a tree like structure. The problem is the only thing i know about each structure is that it can contain one of three things. Strings (the leaf's) Other Objects, Or Lists of other objects. Using reflection i want to do a DFS of the tree until i find a node that im looking for. My problem seems to be that when i use reflection to get a field that happens to be of type List i get back List and i am unable to down cast the the correct type. here are some samples i have tried.

Using Fields

Object returnObj = new Object();
Field field = object.getClass().getDeclaredField(fieldClassName);   
field.setAccessible(true);
List<DistributionPartnerRoleType> test = (List<DistributionPartnerRoleType>) field.get(object);

And using Methods

    String methodName = "get" + Character.toUpperCase(fieldClassName.charAt(0)) + fieldClassName.substring(1);
    Method[] getters = object.getClass().getMethods();
    Method getter = getMethod(getters, methodName);
    Type returnType = getter.getGenericReturnType();
    if(returnType instanceof ParameterizedType){
        Type actualType = ((ParameterizedType) returnType).getActualTypeArguments()[0];
        Class actualClass = (Class) actualType;
        returnObj = getter.invoke(object, null);
        List<Object> newList = new ArrayList<Object>();
        for(Object obj : (List<Object>)returnObj){
              newList.add(actualClass.cast(obj));
        }
        returnObj = newList;
    }

Im aware that the problem is that the objects are truly of type Object but the function and fields are explicitly of type List as declared in the code

protected List<DistributionPartnerRoleType> distributionPartnerRole;

public List<DistributionPartnerRoleType> getDistributionPartnerRole() {
    if (distributionPartnerRole == null) {
        distributionPartnerRole = new ArrayList<DistributionPartnerRoleType>();
    }
    return this.distributionPartnerRole;
}

If anyone knows of a solution for this problem that would be great, Or if i need to go about a different method other then reflection.

edit - code block