Java, MongoDB - Embedded document with REST

Question

I'm building a REST service in Java by using MongoDB ( mongodb-java-driver ), Jersey, and Jackson. An example of the classes I'm using is the following: Employee

public class Employee extends BasicDBObject {
    public Employee() {}
    public Employee(String name, Company company) {
        put("name", name);
        put("company", company);
    }
    public String getName() {
        return get("name").toString();
    }
    public Company getCompany() {
        return (Company) get("company");
    }
    public void setCompany(Company company) {
        put("company", company);
    }
}

Company

public class Company extends BasicDBObject {
    public Company() {}
    public Company(String name, String city) {
        put("name", name);
        put("city", city);
    }
    public String getName() {
        return get("name").toString();
    }
    public String getCity() {
        return get("city").toString();
    }
}

and the REST service

public class EmployeeRestSrv {
    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    public Response createEmployee(Employee employee) {
        DBCollection employeesCollection = DataSource.getDbCollection("employees");
        employeesCollection.setObjectClass(Employee.class);
        // employee.company.name ?
        employeesCollection.insert(employee);
        return Response.ok().build();
    }
}

DataSource is the class that actually creates a connection with MongoDB.

If I send this JSON object with a POST

{
    "employee" : "foo",
    "company" : {
        "name" : "foocompany",
        "city" : "san francisco"
    }
}

I correctly get the document in employeesCollection .

My question is: when in createEmployee at commented line, how can I access the embedded object's fields ( Company )? I also tried employee.get("company").get("name") with no effect.

The final goal is to "force" a sort of One-to-Many relationship and I'd like to be able to store in company document also the list of employees.

Answer 1

Try employee.get("company.name")

That should also work for updating nested documents.

As far as relationships are concerned, this would work as you are storing one-to-many relationships as nested objects.

Answer 2

Try employee.getCompany().getName(); When you say your code "had no effect", what do you mean? (Also, you meant createEmployee , not createUser , right?)

Answer 3

Since BasicDBObject is basically a Map, I implemented this walk-around in Employee class, to obtain the Company structure:

...
public Company getCompany() {
    try {
        return new Company((Map) get("company"));
    } catch(NullPointerException e) {
        return null;
    }
}

public void setCompany(Company c) {
    put("company", c);
}
...

Of course I also created a new constructor in Company, in order to accept Map:

public Company(Map m) {
    super(m);
}