Save Entity Using Foreign Key - spring

Question

I have a question that I hope I can describe clearly. I have the following classes:
#Entity
public class Filter {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
private String name;
#OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY,orphanRemoval = true)
#JoinColumn(name = "filter_id", nullable = false)
private Set<FilterMedication> medications;
//setter and getters are not show
...}
.
#Entity
public class FilterMedication {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
#ManyToOne
#JoinColumn(name = "medication_id", nullable = false)
private Medication medication;
// Setters and getters are not shown
.....}
.
#Entity
#Table(name = "medication")
public class Medication {
#Column(name = "generic_name")
private String genericname;
private String name;
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int id;
// Setters and getters are not shown
.....}
Basically Filters one-to-many relationship with FilterMedicaton, and FilterMedication has many-to-one relationship with Medication.
I created a repository to query for Filters
public interface FilterRepository extends JpaRepository <Filter, Long> {}
I can add a new filter by sending the following JSON object to the save() function
{
"id": 1,
"name": "Test1",
"medications": [
{
"id": 2,
"medication": {
"genericname": "Oxymetazoline HCl Nasal Soln 0.05%",
"name": "12 HOUR NASAL SPRAY 0.05 % NA SOLN",
"strength": "0.05%",
"form": "Solution",
"route": "Nasal"
}
}
]
}
Now time for the question: Is there a way to pass the Medication Foreign Key instead of the complete Medication object, Spring JPA will convert the foreign key to the proper object? The JSON code will be something like this
{
"id": 1,
"name": "Test1",
"medications": [
{
"id": 2,
"FORIGEN KEY": 1
}
]
}
Technically, I can write a function to do so; however, I feel that there is a better and cleaner way to do it.

Answer 1

//convert json to java obj
Filter filter = new Gson().fromjson(yourjson, Filter.class);
//get the fiterMedication (id = 2)
int id = filter.getMedications().getId();
FilterMedication filterMedication = filterMedicationRepository.get(id);
Filter newFilter = new Filter();
newFilter.setId(filter.getId());
....//set name
newFilter.getMedications.add(filterMedication);//get the set of medications and add the element filterMedication
//save newFilter