one to one relationship JPA with multipartfile

I apparently don't know how to do a oneToOne relationship with JPA.

Article entity

@Entity
public class Article {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

private String title;

private String content;

@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "files_id", referencedColumnName = "id")
private MultipartFile file;

File Entity

@Entity
@Table(name = "files")
public class DBFile {
    @Id
    @GeneratedValue(generator = "uuid")
    @GenericGenerator(name = "uuid", strategy = "uuid2")
    private String id;

    private String fileName;

    private String fileType;

    @Lob
    private byte[] data;

    @OneToOne(mappedBy = "files")
    private Article article;

Terminal

Caused by: org.hibernate.AnnotationException: @OneToOne or @ManyToOne on com.test.webservices.article.Article.file references an unknown entity: org.springframework.web.multipart.MultipartFile

I tried to change String by Long to dbfileEntity but I have some trouble to build the uri's path after... I don't understand why it doesn't work since I used @Table annotation.
Could someone explain me?
Thx

It's a typo. Here you're saying you're mapping by files:

@OneToOne(mappedBy = "files")
private Article article;

Where the field name is file:

@OneToOne(cascade = CascadeType.ALL)
@JoinColumn(name = "files_id", referencedColumnName = "id")
private MultipartFile file;

You should fix the mappedBy property:

@OneToOne(mappedBy = "file")
private Article article;

Also the type is wrong, it should be:

private DBFile file;