Hibernate version: 3.2.1
Hello All,
I have 2 objects: DATASTRIP and COUPLINGINFORMATION
Many Datastrips can be coupled by a CouplingInformation object.
One Datastrip can contain many CouplingInformation objects to be coupled to other Datastrips
Mapping documents:
DATASTRIP:
Code:
@Entity
public class DataStrip implements Serializable {
private Integer dataStripId; //PK
private Collection<CouplingInformation> couplingInformationList = new HashSet<CouplingInformation>();
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="datastrip_id")
public Integer getDataStripId() {
return dataStripId;
}
@ManyToMany(
cascade=CascadeType.ALL,
fetch = FetchType.LAZY,
targetEntity=CouplingInformation.class
)
@JoinTable(
name="datastrip_coupling",
joinColumns={@JoinColumn(name="datastrip_id")},
inverseJoinColumns={@JoinColumn(name="couplinginformation_id")}
)
public Collection<CouplingInformation> getCouplingInformationList() {
return couplingInformationList;
}
public void setCouplingInformationList(
Collection<CouplingInformation> couplingInformationList) {
this.couplingInformationList = couplingInformationList;
}
COUPLINGINFORMATION:
Code:
@Entity
public class CouplingInformation implements Serializable {
private Integer couplingInformationId; //PK
private Collection<DataStrip> dataStripList = new HashSet<DataStrip>();
@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
@Column(name="couplinginformation_id")
public Integer getCouplingInformationId() {
return couplingInformationId;
}
[b]
@ManyToMany(
cascade=CascadeType.ALL,
fetch = FetchType.LAZY,
mappedBy="couplingInformationList",
targetEntity=DataStrip.class
)
[/b]
public Collection<DataStrip> getDataStripList() {
return dataStripList;
}
public void setDataStripList(Collection<DataStrip> dataStripList) {
this.dataStripList = dataStripList;
}
If I do the ManyToMany coupling in CouplingInformation with mappedBy, it does NOT work.
I have a test fuction that does follows:
- I create a CouplingInformation.
- I create 2 DataStrips.
- I add the 2 DS into the CI and persist everything.
After that I check everything is well persisted.
There are 2 DS in the database, there is a new CI in the database.
But there are no entries in the intermediate table 'datastrip_couplinginformation'After hours of trying, fighting, experimenting I did this:
I replaced the 'mappedBy' property by another @JoinTable Annotation.
Code:
[b]
@ManyToMany(
cascade=CascadeType.ALL,
fetch = FetchType.LAZY,
targetEntity=DataStrip.class
)
@JoinTable(
name="datastrip_coupling",
joinColumns={@JoinColumn(name="couplinginformation_id")},
inverseJoinColumns={@JoinColumn(name="datastrip_id")}
[/b]
public Collection<DataStrip> getDataStripList() {
return dataStripList;
}
And now the intermediate table is filled in as it should be !!!
Is there any reasonable explenation for such a behaviour ?
I have a secondary problem:
Furtheron the testcode, I take one of the two DataStrips that just got persisted and I do a
assertEqual("couplinginf.size=1", 1, ds.getCouplingInformationList.size());
The test always fails when I do that, it shows 0
If I enhance the code with following:
Code:
public void setDataStripList(Collection<DataStrip> dataStripList) {
this.dataStripList = dataStripList;
for (DataStrip datastrip : dataStripList) {
datastrip.getCouplingInformationList.add(this);
}
}
The insert operation fails because now Hibernate wants to insert the combination in the intermediate table a second time (and encounters a pk key exception of the db)
How can I make it work that a CI is shown for a DS that is just being added by the same CI ?
Jan
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