How to convert this UML to JPA entities

Question

I have this UML diagram.

And I tried to build entities like this (I renamed Entity class to Entidad)

RelationshipType.java

@Entity
@Table(name = "relationship_type")
public class RelationshipType {

    @Id
    @GeneratedValue
    private Long id;

    private String type;

    @OneToMany(mappedBy = "relationshipType", fetch = FetchType.EAGER)
    private Set<Relationship> relationships = new HashSet<Relationship>();
    //Getters and Setters

Relationship.java

@Entity
@Table(name = "relationship")
public class Relationship {

    @Id
    @ManyToOne
    private RelationshipType relationshipType;

    @Id
    @ManyToOne
    private Entidad entity;
    //Getters and Setters

Entidad.java

@Entity
@Table(name = "entity")
public class Entidad {
    @Id
    @GeneratedValue
    private Long id;

    private String image;

    private String foundationNotes;

    private String alias;

    private Boolean excludeNotifications;

    private String notes;

    //[...]

    @ManyToOne 
    private Relationship related;

    @OneToMany(mappedBy = "entity", fetch = FetchType.EAGER)
    private Set<Relationship> relationships = new HashSet<Relationship>();

But when I launch app throws this:

Foreign key (FK_9d8afoh1pv9r59iwjkbcpnud1:entity [])) must have same number of columns as the referenced primary key (relationship [relationshipType_id,entity_id])

At now, I don't know where is the problem and need do this well because I'm using this entities to build the DB schema.