4

我尝试了各种方法，例如最简单的：

// Value object
@Embeddable
@NoSql(dataFormat=DataFormatType.MAPPED)
public class Attribute implements Serializable {

   @Basic
   private String someProp;

   // ... getter/setter omitted
}

@Entity
@NoSql(dataFormat=DataFormatType.MAPPED)
public class FancyEntity implements Serializable {

   @Id
   @GeneratedValue
   @Field(name="_id")
   private String id;

   @ElementCollection
   private Map<String,Attribute> attributes = new HashMap<>();

   // ... getter/setter omitted
}

但这会产生错误：

Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.4.1.v20120825fb0a20b): org.eclipse.persistence.exceptions.EntityManagerSetupException
Exception Description: Predeployment of PersistenceUnit [myPersistenceUnit] failed.
Internal Exception: java.lang.ClassCastException: org.eclipse.persistence.eis.mappings.EISCompositeCollectionMapping cannot be cast to org.eclipse.persistence.mappings.foundation.MapComponentMapping
at org.eclipse.persistence.exceptions.EntityManagerSetupException.predeployFailed(EntityManagerSetupException.java:221)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.createPredeployFailedPersistenceException(EntityManagerSetupImpl.java:1541)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:1532)
at org.eclipse.persistence.jpa.PersistenceProvider.createContainerEntityManagerFactory(PersistenceProvider.java:208)

任何的想法？

我在 Glassfish 3.1.2 上使用最新的 2.4.1-SNAPSHOT。

解决方案

添加 @MapKey 注释并在可嵌入类中选择所需的键字段：

   @ElementCollection
   @MapKey(name="name")
   private Map<String,Attribute> attributes = new HashMap<>();
4

1 回答 1

2

您应该能够使用 @MapKey 从 Attribute 对象定义映射键（我假设它的名称）。

EclipseLink 当前的 NoSQL 支持不支持 @MapKeyColumn、@MapKeyJoinColumn 和 @MapKeyClass。

请记录有关异常的错误，您应该得到更好的错误，或者应该更好地默认映射键。

于 2012-09-04T13:48:49.757 回答