Use the external key as part of primary key with Hibernate annotation

Question

I have a one-to-many relationship between Car and DatatableProgress , so one car may have more DatatableProgress but one DatatableProgress element is of one car . Car has idCar as primary key, datatableProgress has datatableName and sheet as primary key, but I have to add idCar (the foreign key) as part of primary key. I tryed with this code but I received mappedBy reference an unknown target entity property: com.domain.DatatableProgress.car in com.domain.Car.datatablesProgress . I need this because I can have a datatableProgress with the same name and sheet but different car. :

DatatableProgress :

@Entity
@Table(name = "datatableprogress")
public class DatatableProgress implements Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;


    private DatatableProgressKeys datatableProgressKeys;
    private Integer actualStoredRow;    

    @MapsId("car")
    @JoinColumns({
        @JoinColumn(name="idCar_fk", referencedColumnName="idCar"),
    })
    @ManyToOne(fetch = FetchType.LAZY) 
    private Car car;

    public DatatableProgress() {
    }


    public DatatableProgress(DatatableProgressKeys datatableProgressKeys, Integer actualStoredRow) {
        this.datatableProgressKeys = datatableProgressKeys;
        this.actualStoredRow = actualStoredRow;
    }


    /**
     * @return the datatableKeys
     */
    @EmbeddedId
    public DatatableProgressKeys getDatatableProgressKeys() {
        return datatableProgressKeys;
    }


    /**
     * @param datatableKeys the datatableKeys to set
     */
    public void setDatatableProgressKeys(DatatableProgressKeys datatableProgressKeys) {
        this.datatableProgressKeys = datatableProgressKeys;
    }


    @Column(name = "actualStoredRow", nullable = false)
    public Integer getActualStoredRow() {
        return this.actualStoredRow;
    }

    public void setActualStoredRow(Integer actualStoredRow) {
        this.actualStoredRow = actualStoredRow;
    }
}

DatatableProgressKey

@Embeddable
public class DatatableProgressKeys implements Serializable {
    private static final long serialVersionUID = 1L;
    private String datatableName;
    private Integer sheet;
    private Car car;


    public DatatableProgressKeys() {}

    public DatatableProgressKeys(String datatableName, Integer sheet, Car car) {
        this.datatableName = datatableName;
        this.sheet = sheet;
        this.setCar(car);
    }


    @Column(name = "datatableName", nullable = false)
    public String getDatatableName() {
        return this.datatableName;
    }

    public void setDatatableName(String datatableName) {
        this.datatableName = datatableName;
    }


    @Column(name = "sheet", nullable = false)
    public Integer getSheet() {
        return this.sheet;
    }

    public void setSheet(Integer sheet) {
        this.sheet = sheet;
    }

    /**
     * @return the car
     */
    @Column(name = "id_car", nullable = false)
    public Car getCar() {
        return car;
    }

    /**
     * @param car the car to set
     */
    public void setCar(Car car) {
        this.car = car;
    }

//hashCode and equals 

Car

@Entity
@Table(name = "car")
public class Car implements java.io.Serializable {

    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private Integer idCar;
    private Integer initialKm;

    @JsonIgnore
    private Set<DatatableProgress> datatablesProgress = new HashSet<DatatableProgress>(0);

    public Car() {
    }

    public Car(Integer initialKm) {
        this.initialKm = initialKm;
    }

    @Id
    @GeneratedValue(strategy = IDENTITY)
    @Column(name = "id_car", unique = true, nullable = false)
    public Integer getIdCar() {
        return this.idCar;
    }

    public void setIdCar(Integer idCar) {
        this.idCar = idCar;
    }

    @Column(name = "initialKm", nullable = false)
    public Integer getInitialKm() {
        return this.initialKm;
    }

    public void setInitialKm(Integer initialKm) {
        this.initialKm = initialKm;
    }

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "car")
    public Set<DatatableProgress> getDatatablesProgress() {
        return this.datatablesProgress;
    }

    public void setDatatablesProgress(Set<DatatableProgress> datatablesProgress) {
        this.datatablesProgress = datatablesProgress;
    }
}

UPDATE: Is it possible to make this change without modify Car entity (so without CarKey class)?

Answer 1

To be a part of composite key entity should be @Embedable. You can create a separate key entity for a Car class just with one Integer field and then use this key class for your composite key. See there Hibernate docs