nested exception is org.hibernate.AnnotationException: mappedBy reference an unknown target entity property

Question

Based on this tutorial I'm trying to create Many-to-Many Relationship Using a Composite Key Eventually I get the following error

The composite key itself have the following structure:

@Embeddable
@Data
public class MovieRatingsKey implements Serializable {

    @Column(name = "movieid")
    private Movies movieid;

    @Column(name = "userid")
    private Usrs userid;
}

Class Movies:

@Entity
@Data
public class Movies {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer movieid;

    /*not related to the question*/

    @OneToMany(mappedBy = "movieid", fetch = FetchType.LAZY)
    private Set<Ratings> rates = new HashSet<>();
}

User:

@Entity
@Data
public class Usrs {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer userid;

    @OneToMany(mappedBy = "userid", fetch = FetchType.LAZY)
    private Set<Ratings> rates = new HashSet<>();
}

Associative table:

@Entity
@Data
public class Ratings {
    @EmbeddedId
    private MovieRatingsKey id;
    
    /*not related to the question*/

    @ManyToOne
    @MapsId("movieid")
    @JoinColumn(name = "movieid")
    Movies movie;

    @ManyToOne
    @MapsId("userid")
    @JoinColumn(name = "userid")
    Usrs user;
}

Answer 1

In your Usrs you have used userid in mappedBy is should be user as shown below.

@Entity
@Data
public class Usrs {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer userid;

    @OneToMany(mappedBy = "user", fetch = FetchType.LAZY)
    private Set<Ratings> rates = new HashSet<>();
}