Can't save entity Embeddable Id

Question

I have EcranChamp entity

@Entity
@IdClass(EcranChampId.class)
public class EcranChamp {

@Id
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "ecran")
Ecran ecran;


@Id
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "champ")
Champ champ;

...

And EcranChampId

@Embeddable
public class EcranChampId implements Serializable  {    
private Champ champ;  
private Ecran ecran;
...

Every time i am trying to save an EcranChamp element i have this following error

2018-09-25 12:15:42.889 WARN 14216 --- [nio-8092-exec-8] .w.s.m.s.DefaultHandlerExceptionResolver : Failed to convert request element: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.Long' to required type 'com.kepler.portailclient.domain.model.Ecran' for property 'ecran'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.Long' to required type 'com.kepler.portailclient.domain.model.Ecran' for property 'ecran': no matching editors or conversion strategy found 2018-09-25 12:15:42.889 WARN 14216 --- [nio-8092-exec-8] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved exception caused by Handler execution: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'java.lang.Long' to required type 'com.kepler.portailclient.domain.model.Ecran' for property 'ecran'; nested exception is java.lang.IllegalStateException: Cannot convert value of type 'java.lang.Long' to required type 'com.kepler.portailclient.domain.model.Ecran' for property 'ecran': no matching editors or conversion strategy found

Answer 1

Try something like this:

@Entity
@Table(name = "<entity name>")
public class EcranChamp {

    @EmbeddedId
    @AttributeOverrides({ @AttributeOverride(name = "id_ecran", column = @Column(name = 
        "<column name>", nullable = false)),
    @AttributeOverride(name = "id_champ", column = @Column(name = "<column name>", nullable = false)) })
    EcranChampId id

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "id_ecran")
    Ecran ecran;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "id_champ")
    Champ champ; 
   //getters & setters 
 }   


@Embeddable
public class EcranChampId implements Serializable  {   
  @Column(name = "id_champ", nullable = false) 
  private Long id_champ; 
  @Column(name = "id_ecran", nullable = false)  
  private Long id_ecran; 
  //getters & setters 
}