How to retrieve multiple entries from table into one list?

Question

thanks for helping ;)

I'm new to hibernate and wanna try it for my private project.
What i want to do is: I want to have a class like

public class Playlist {
    private long id;
    private String name;
    private long owner_ID;
    private ArrayList<String> urls;
}

Where the list should contain urls to some songs.

At the moment I have one entry in my db for each url. Is there a better way to do that? And to my main question: How can I recieve/save the list?

I can get a "normal" table entry rn but I haven't worked with Hibernate and Lists/ArrayLists in combination jet.

Hope you can help me ;)

If additional information is required feel free to ask.

Answer 1

Since the urls is a basic value (String) you can use @ElementCollection.

@Entity
public class Playlist {
    @Id
    private Long id;
    private String name;
    private long owner_ID;
    
    @ElementCollection
    private List<String> urls;
}

This mapping links two tables:

• playlist table which has id, name, owner_ID columns
• playlist_urls table which has playlist_id and urls columns.

For more information take a look at here.