如何使用@OneToOne将不同的实体作为属性添加到对象

Question

I have two entities in my application: House and Photo .

House has a property mainPhoto which has a @OneToOne relation to Photo

Everything works fine here. Now I want to create a form for an admin where he will be able to add a new House . I want to add an upload field where he can select a Photo .

How can I get this Photo , put it in a table named photo (create an object from it with some predefined values + this photo) and set the relationship between them?

Answer 1

This should be rather trivial in JPA.

After the upload, instantiate a Photo object and assign it to the mainPhoto property of House . Then just merge the result into the persistent context. Make sure you have merge cascading enabled on the relation.

Basically something along the lines of:

Photo photo = new Photo();
// set photo properties according to uploaded file

house.setMainPhoto(photo);
entityManager.merge(house);