$/**$

$*$ This is an ORM entity for an Artist. Artists have a one$-$to$-$many relationship with albums $($one artist can produce

$*$ many albums$).$ This is reflected in the @OneToMany annotation. Spring Data JPA will associate these entities $($and

$*$ their database tables$)$ with each other according to the specified relationship. This is done with foreign keys, but

$*$ we are abstracted away from that behavior. If we wish to find the albums written by a particular artist, JPA will

$*$ perform a join with the Album table to retrieve the artists. All that is needed to retrieve a List of the related

$*$ albums is to call the method artist.getAlbums$().$

$*/$

@Entity

$//$For the sake of brevity, the following $4$ annotations tell Lombok to generate boilerplate code at compile$-$time.

@EqualsAndHashCode

@NoArgsConstructor

@AllArgsConstructor

@Data

public class Artist $\{$

$//$The GeneratedValue annotation allows for Spring to automatically generate a unique ID$.$

$$ @Id

$$ @GeneratedValue$($strategy $=$ GenerationType.IDENTITY$)$

$$ private long artistId;

$$ private String name;

$/**$

$*$ There is one artist for many albums.

$*$ They will be connected via a foreign key by the name "album$\_$fk$",$ belonging to the Album table.

$*$ Spring will automatically perform the logic needed to join the Album and Artist table to get related albums.

$*/$

$$ @OneToMany$($fetch $=$ FetchType.EAGER$)$

$$ @JoinColumn$($name $=$ "artist$\_$fk$")$

$$ private List albums;

$$ public Artist$($String name$)\{$

$$ this.name $=$ name;

$\}$

$/**$

$*$ A custom toString$()$ is provided that avoids recursively serializing related entities.

$*/$

$$ @Override

$$ public String toString$()\{$

$$ return "Artist$\{"+$

$$ "artistId$="+$ artistId $+$

$",$ name$=\text{'}"+$ name $+\text{'}\backslash \text{'}\text{'}+$

$\text{'}\}\text{'}$;

$\}$

$\}$