POSTing nested objects using spring data rest?

Question

I have recently started using spring-data-rest for my application. I have the following JPA entities:

@Entity
public class Super {
    @Id
    private long id;

    @JoinTable
    @OneToMany(cascade = CascadeType.ALL)
    private List<Child> children;
}

-----------------------------------------

@Entity
public class Super2 {
    @Id
    private long id;

    @JoinTable
    @OneToMany(cascade = CascadeType.ALL)
    private List<Child> children;
}

-----------------------------------------

@Entity
public class Child {
    @Id
    private long id;

    @Column
    private String childMetadata;
}

I can think of 2 methods of saving new instances of Super or Super2:

1. Expose a @RestResource for Child class -> Create all the instances of Child before creating instances of Super or Super2 -> Pass the URLs of all the Child instances in payload of Super or Super2.
2. Pass the details of Child in the payload of Super or Super2 without exposing @RestResource for Child class and the CascadeType.ALL will take care of creating Child instances.

There are some pros with both the methods:

1. With option 1, I get an ability to add new Child objects to Super or Super2 just by POSTing the url of new Child to http://<server>:<port>/super/1/children. But I definitely loose the cascading functionality of database if I use this method.
2. With option 2, I get all the cascading functionalities of database but I loose the flexibility of adding new Child instances.

Is there something I have totally missed? I want a way to use the cascading functionality of database without loosing the flexibility of adding new children on the fly.

Thanks for help. :)

Answer 1

There is a third solution that should fit for you:

3. Pass the details of Child in the payload of Super or Super2 without exposing @RestResource for the attribute 'children' of Super (and Super2).

You'll still can use /children, but you will be able to retrieve children with super and to post it!

To do this, just change your Super (and Super2) class like this:

public class Super {
    @Id
    @GeneratedValue
    private Long id;

    @JoinTable
    @OneToMany(cascade = CascadeType.ALL)
    @RestResource(exported=false)
    private List<Child> children;

    ...
}

Then you can POST on /supers:

{
    "children": [
        {
            "childMetadata": "inner"
        }
    ]
}