In one of my classes(A), I have a composite ID. This composite ID consists of 2 fields: one String (f1) and one Integer(f2), which is a foreign key to another entity(B) and has a many-to-one relation to the ID of the B entities. (like key-many-to-one property of composite key in the classical hibernate)
My mappling:
Code:
@Entity
@Table(name="ATABLE")
public class A implements java.io.Serializable{
...
@EmbeddedId
@AttributeOverrides( {
@AttributeOverride(name="f1", column=@Column(name="f1", unique=false, nullable=false, insertable=true, updatable=true, precision=22, scale=0) ),
@AttributeOverride(name="f2", column=@Column(name="f2", unique=false, nullable=false, insertable=true, updatable=true, precision=22, scale=0) ) } )
public AId getId() {
return this.id;
}
public void setId(AId id) {
this.id = id;
}
...
}
public class AId implements java.io.Serializable {
private String f1;
@ManyToOne
@JoinColumn (name="f2", referencedColumnName="f2")
private B f2;
public String getF1() {
return this.f1;
}
public void setF1(String f1) {
this.f1 = f1;
}
public BgetF2() {
return this.f2;
}
public void setF2(B f2) {
this.f2 = f2;
}
...
}
@Entity
@Table(name="BTABLE")
public class B implements java.io.Serializable {
@Id
private Integer f2;
...
}
If I try to get an instance of class A, I get an error:
Code:
org.hibernate.type.SerializationException: could not deserialize
at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:217)
at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:240)
at org.hibernate.type.SerializableType.fromBytes(SerializableType.java:78)
at org.hibernate.type.SerializableType.get(SerializableType.java:39)
at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:113)
at org.hibernate.type.NullableType.nullSafeGet(NullableType.java:102)
at org.hibernate.type.AbstractType.hydrate(AbstractType.java:81)
at org.hibernate.type.ComponentType.hydrate(ComponentType.java:506)
at org.hibernate.type.ComponentType.nullSafeGet(ComponentType.java:229)
at org.hibernate.loader.Loader.getKeyFromResultSet(Loader.java:1088)
at org.hibernate.loader.Loader.getRowFromResultSet(Loader.java:554)
at org.hibernate.loader.Loader.doQuery(Loader.java:689)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.doList(Loader.java:2145)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2029)
at org.hibernate.loader.Loader.list(Loader.java:2024)
at org.hibernate.loader.criteria.CriteriaLoader.list(CriteriaLoader.java:95)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1562)
at org.hibernate.impl.CriteriaImpl.list(CriteriaImpl.java:283)
at mypackage.myDAO.search(Search.java:123)
Caused by: java.io.StreamCorruptedException: invalid stream header
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:753)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:268)
at org.hibernate.util.SerializationHelper$CustomObjectInputStream.<init>(SerializationHelper.java:252)
at org.hibernate.util.SerializationHelper.deserialize(SerializationHelper.java:209)
... 35 more
If I change the AId Class definition to
Code:
public class AId implements java.io.Serializable {
private String f1;
private Integer f2;
public String getF1() {
return this.f1;
}
public void setF1(String f1) {
this.f1 = f1;
}
public Integer getF2() {
return this.f2;
}
public void setF2(Integer f2) {
this.f2 = f2;
}
...
}
then I can get instances of the class A. But how can I map the part of the composite key which is simultaneously a foreign key to another entity with EJB 3.0 Annotations? All my entity classes and the composite ID are implement java.io.Serializable.
Thank you.
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