持續時間複製實體ID

Question

我想將運行時生成的實體UUID複製到另一個字段。 實體ID經由代碼生成描述如下：

package eclipselink.example; 
public class UUIDSequence extends Sequence implements SessionCustomizer { 
    public UUIDSequence() { 
     super(); 
    } 
    public UUIDSequence(String name) { 
     super(name); 
    } 
    @Override 
    public Object getGeneratedValue(Accessor accessor, 
      AbstractSession writeSession, String seqName) { 
     return UUID.randomUUID().toString().toUpperCase(); 
    } 
    ... 
    public void customize(Session session) throws Exception { 
     UUIDSequence sequence = new UUIDSequence("system-uuid"); 
     session.getLogin().addSequence(sequence); 
    } 
} 

Persitence.xml：

property name="eclipselink.session.customizer" value="eclipselink.example.UUIDSequence" 

實體：

public abstract class MyEntity{ 
    private String id; 
    private String idCopy; 

    @Id 
    @Basic(optional = false) 
    @GeneratedValue(generator="system-uuid") 
    @XmlElement(name = "ID") 
    public String getId() { 
     return id; 
    } 
} 

如何可以指示JPA（Eclipse的鏈路）將運行時生成的UUID複製到idCopy字段？

Answer 1

我不是100％肯定這將工作（我不知道的EclipseLink調用調節器或現場直接分配），但是這給一試：

public abstract class MyEntity{ 
    private String id; 
    private String idCopy; 

    @Id 
    @Basic(optional = false) 
    @GeneratedValue(generator="system-uuid") 
    @XmlElement(name = "ID") 
    public String getId() { 
     return id; 
    } 

    public void setId(String id) { 
     this.id = id; 
     this.idCopy = id; 
     // or 
     // this.setIdCopy(id); 
    } 
}