如何使用Eclipselink Mongodb映射Dynamic Json对象

Question

我正在尝试将动态JSON内容映射到Java对象，使用eclipse-link将其保存在Mongo数据库中，我使用Map如下

@Entity
@NoSql(dataFormat = DataFormatType.MAPPED)
public class MyCollection {

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

    @Temporal(TemporalType.TIMESTAMP)
    @Field(name = "CreatedOn")
    private Date createdOn;

    @ElementCollection
    @Field(name = "Attributes")
    private Map<String, Object> attributes;

    // Getters and Setters
}

但是它给出了错误

Exception [EclipseLink-7155] (Eclipse Persistence Services - 2.6.1.v20150916-55dc7c3): org.eclipse.persistence.exceptions.ValidationException
Exception Description: The type [class java.lang.Object] for the attribute [attributes] on the entity class [class demo.MyCollection] is not a valid type for a serialized mapping. The attribute type must implement the Serializable interface.
    at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionSearchingForPersistenceResources(PersistenceUnitLoadingException.java:127)
    at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactoryImpl(PersistenceProvider.java:115)
    at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:188)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
    at test.Mongo.createEntityManager(Mongo.java:26)
    at test.Mongo.<init>(Mongo.java:22)
    at test.TestMongoOrm.<init>(TestMongoOrm.java:11)
    at test.TestMongoOrm.main(TestMongoOrm.java:13)

任何想法如何解决这个问题？