Java can';在应用程序引擎中持久化jpa实体
我认为您需要添加一个Java can';在应用程序引擎中持久化jpa实体,java,google-app-engine,jpa,Java,Google App Engine,Jpa,我认为您需要添加一个cascade属性,以便JPA提供者可以在添加到blob的新Blobx上进行cascade持久化。目前,正如错误消息所报告的那样,JPA提供者不能。因此,可以这样更改它(调整级联类型,以满足您的需要): @OneToMany(cascade=CascadeType.ALL) 私有列表blob; @Entity public class Blobx { private String name; private BlobKey bl
cascade
属性,以便JPA提供者可以在添加到blob
的新Blobx
上进行cascade持久化。目前,正如错误消息所报告的那样,JPA提供者不能。因此,可以这样更改它(调整级联类型
,以满足您的需要):
@OneToMany(cascade=CascadeType.ALL)
私有列表blob;
@Entity
public class Blobx {
private String name;
private BlobKey blobKey;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
//getters and setters
}
@Entity
public class Userx {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Key id;
private String name;
@OneToMany
private List<Blobx> blobs;
//getters and setters
}
java.lang.IllegalStateException: Field "entities.Userx.blobs" contains a persistable object that isnt persistent, but the field doesnt allow cascade-persist!
@OneToMany(cascade = CascadeType.ALL)
private List<Blobx> blobs;