Produce JSON by RESTful web service in Spring Boot?

My problem: I don't return JSON but an array.

So, I will want JSON to be returned.

My repository interface:

public interface SuiRepository extends JpaRepository<Folder, Integer> {@Query("...")    public List<Folder> data();}

My getFolder method:

@Overridepublic List<Folder> getFolder() {    List<Folder> s = folderRepository.data();    return s;}

My Rest Service:

@RequestMapping(value="/folders", method=RequestMethod.GET, produces="application/json", consumes="application/json")@ResponseBodypublic  List<Folder> getFolders() {    return iUd.getFolders();}

My Folder class:

@Entitypublic class Folder implements Serializable {    @Id    @GeneratedValue(strategy=GenerationType.AUTO)    private int idFolder;     private String comments;    @ManyToOne    @JoinColumn(name="IdFile")    private File file;    @ManyToOne    @JoinColumn(name="username")    private User user;    /* Getters & Setters... */} 

The current return:

[  ["Ban", "dee", "dede@gmail.com", 1, "xx", "Emb"],  ["Cin", "mis", "sse@gmail.com", 1, "yy", "Ns"]]

Thanks!