Duplicating Realm class under new class name

Question

I have a class Message.java:

public class Message extends RealmObject implements Serializable {

    @PrimaryKey
    @SerializedName("id")
    @Expose
    private Integer id;

    @SerializedName("user_id")
    @Expose
    private User user;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

}

However, when saving Message objects in Realm, I want to save them under a different class name, NotificationMessage (which should have all the same properties and methods as the Message class), like:

public class NotificationMessage extends Message {

}

But this doesn't seem to work. How can I create the NotificationMessage class without copying and pasting all of the properties and methods of the Message class?

Can you include the code you used to save, which does not work? — Doug, Feb 17 '17 at 02:03
It is not possible for now. There is an issue tracking this: https://github.com/realm/realm-java/issues/1470 If you really want to do that, you need to parse the json manually and save to Realm. — beeender, Feb 17 '17 at 03:20

score 1 · Answer 1 · answered Feb 17 '17 at 02:09

It seems that you hit this issue https://github.com/realm/realm-java/issues/761

Currently, Realm doesn't support that kind of inheritance, but what some people in that thread did was to use an Interface which holds all the methods that are common to your classes.

In your particular case, you have to convert NotificationMessage into an interface to hold the methods of Message and then make Message implements the NotificationMessage .

public interface NotificationMessage {


    public Integer getId() ;

    public void setId(Integer id) ;

    public User getUser() ;

    public void setUser(User user) ;

}



public class Message extends RealmObject implements Serializable, NotificationMessage {

    @PrimaryKey
    @SerializedName("id")
    @Expose
    private Integer id;

    @SerializedName("user_id")
    @Expose
    private User user;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

}

Duplicating Realm class under new class name

1 Answers1