Spring: Handle child collection update the right way - spring

Question

Let's say that I manage an online shop. I want to be able to add and update products via a REST API.
The expected DTO would be something like this:
{
"id": 1,
"name": "iPhone 11 Pro",
"price": 999,
"pictures": [
{
"url": "http://image.com/image1.jpg",
"description": "image 1"
},
{
"url": "http://image.com/image2.jpg",
"description": "image 2"
}
]
}
Using JPA, this would require the 2 following entities:
#Entity
public class Product {
private Long id;
private String name;
private Integer price;
#OneToMany(mappedBy="product")
private List<ProductPicture> pictures;
}
#Entity
public class ProductPicture {
private Long id;
#ManyToOne
private Product product;
private String url;
private String description;
}
How to handle a product update? In all tutorials / sample codes I find, it's always a very basic example with a single entity having no collection.
I think about some options:
retrieve the product from DB, empty the "pictures" list and refill it, then save;
retrieve the product from DB, iterate over all pictures to find matches then remove/add what is needed, then save;
maybe that there is a Spring/Hibernate magic for handling this?
I don't like the 2 first ones.
I'm almost thinking to opt for a NoSQL database since it would be a lot easier for this use case... even if it's probably not a good reason.
Also, I'm not in favor of using a dedicated endpoint for this (like POST or DELETE on /products/1/pictures).
Could you please share a sample code to handle the update using Spring / Hibernate?
Thanks!

Answer 1

I finally ended up using the #Embeddable and #ElementCollection annotations that I didn't know, which looks to be a perfect fit for what I wanted to do.
#Entity
public class Product {
private Long id;
private String name;
private Integer price;
#ElementCollection(fetch = FetchType.EAGER)
private List<ProductPicture> pictures;
}
#Embeddable
public class ProductPicture {
private String url;
private String description;
}
This way the update is super-easy:
Product dbProduct = productRepository.findById(product.getId()).get();
// ...
dbProduct.setPictures(product.getPictures());
productRepository.save(dbProduct);