Ebean中的@OneToMany关系

Question

I'm trying to write a system which contains people and applications. Every person can apply for different applications.

I'm trying to apply a @oneToManyRelation on the person object (when retriving a person from the db, I would like to recive a list with every aplication that they applied for).

Here is my code:

@Entity
@Table(name="t_person")
public class person extends Model {
    @id
    @column(name="PERSON_ID")
    private string ID;

    more properties...

    @OneToMany(targetEntity=application.class, mappedBy="SOLDIER_ID")
    private ArrayList<application> ApplicationList;

    public ArrayList<application> getApplicationList() {
        return ApplicationList;
    }

    public void setApplicationList(ArrayList<application> applicationList) {
        ApplicationList = applicationList;
    }
}

@Entity
@Table(name="T_APPLICATION")
public class application extends Model {
        @Id
        @Column(name="APPLICATION_ID")
        private int Id;

        @ManyToOne
        @JoinColumn(name="PERSON_ID")
        private person Person;
}

I'm using Activator and an Oracle DB. When I retrieve an application I get the person object ok, but when retriving a person, the application list is null.

Where am I going wrong?

Answer 1

Use mappedBy on your annotation for reverse attributes; it's not the column name you should use here but the name of the attribute on other object.

On Person:

@OneToMany(mappedBy = "person", fetch = FetchType.EAGER)
ArrayList<Application> applicationList;

On Application:

@ManyToOne
Person person;

You may need to add @JoinColumn where applicable. As said in comments, fetch = FetchType.EAGER shoudl help too.

Answer 2

i found the problem. the problem is that applicationList is an ArrayList<> and not a List<>. as soon as i change the ArrayList to a List. it's working.