Convert enhanced for each loop to streams java 8

I am trying to convert code written in enhanced for each loop to streams in java.
Here is my traditional code

    List<OrderDetail> orderDetails = new ArrayList<>();
	if (arInvoiceOrderResponseBody != null) {
		if (arInvoiceOrderResponseBody.getOrders() != null && 
         arInvoiceOrderResponseBody.getOrders().size() > 0) {
         for (OrderDetail orderDetail : arInvoiceOrderResponseBody.getOrders()) {
				if (orderDetail != null) {
					if (orderDetail.getStatusHistory() != null && 
                        orderDetail.getStatusHistory().size() > 0) {
						for (StatusHistory statusHistory : orderDetail.getStatusHistory()) {
							if (statusHistory != null) {
								if (statusHistory.getStatusCode() != null) {
									if (statusHistory.getStatusCode().equals("POD")) {
										orderDetail.setStatusDateTime(statusHistory.getStatus_date_time());
									}
								}

							}
						}
					}
				}
				orderDetails.add(orderDetail);
			}
			arInvoiceOrderResponseBody.setOrders(orderDetails);
		}

Can anyone help me on replicating same functionality through streams.Any help would be greatly helpful

This is what i am trying

    arInvoiceOrderResponseBody.getOrders().stream() .flatMap(order ->
    order.getStatusHistory().stream()) 
    .filter(statusHistory ->statusHistory.getStatusCode().equals("POD"))
    //Here if condition is true then i need to do this.I need to set one
    //of the property of main order object to one of the property of status 
    //history object 
    //order.setStatusDateTime(statusHistory.getStatus_date_time());

Following is about as Java-8 as this is going to get in my opinion.

arInvoiceOrderResponseBody.getOrders().forEach(
      orderDetail -> orderDetail.getStatusHistory().stream()
        .filter(statusHistory -> "POD".equals(statusHistory.getStatusCode()))
        .findFirst()
        .ifPresent(statusHistory -> orderDetail.setStatusDateTime(statusHistory.getStatus_date_time()))
    );

I note the original code changes the existing OrderDetail instances but then puts them (all) into a new collection and replaces the original collection. This seems pointless on the face of it!

Splitting it out into multiple methods and breaking it down into two streams may work. Something like:

  public static ResponseBody processResponseBody(ResponseBody responseBody)
{
if(validate(responseBody))
{
List<OrderDetail> orderDetails = responseBody.getOrders().stream()
.filter(od -> validate(od))
.map(od -> processOrderDetail(od))
.collect(Collectors.toList());
responseBody.setOrders(orderDetails);
}
return responseBody;
}
private static OrderDetail processOrderDetail(OrderDetail orderDetail)
{
StatusHistory statusHistory = orderDetail.getStatusHistory().stream()
.filter(sh -> validate(sh))
.findFirst()
.orElseThrow(() -> new IllegalArgumentException("No Status History Found"));
orderDetail.setStatusDateTime(statusHistory.getStatus_date_time());
return orderDetail;
}
private static boolean validate(ResponseBody responseBody)
{
return responseBody != null && responseBody.getOrders() != null && responseBody.getOrders().size() > 0;
}
private static boolean validate(OrderDetail orderDetail)
{
return orderDetail != null && orderDetail.getStatusHistory() != null && orderDetail.getStatusHistory().size() > 0;
}
private static boolean validate(StatusHistory statusHistory)
{
return statusHistory != null && statusHistory.getStatusCode() != null && statusHistory.getStatusCode().equals("POD");
}

I broke it into a stream to process the OrderDetail object and a stream to reduce the StatusHistory to a single object. I also broke the validation into their own methods for brevity and organization.