I have an Hibernate Entity Object Class for the table deviceinfo with columns
**deviceinfo
{
id(primary),
devicecarid,
status,
name
}**
Java Hibernate Entity as follows
Code:
@XmlRootElement(name = "device")
@Entity
@Table(name="deviceinfo")
public class DeviceInfo implements Serializable, Comparable<DeviceInfo > {
@ManyToMany(cascade={CascadeType.PERSIST, CascadeType.MERGE})
@JoinTable(
name="VehicleDeviceCar",
joinColumns={@JoinColumn(name="devicecarid", referencedColumnName="devicecarid", unique=false, insertable = false, updatable = false)},
inverseJoinColumns={@JoinColumn(name="vehicleId", referencedColumnName="vehicleId", insertable = false, updatable = false)}
)
@XmlElement(name="vehicles")
public Set<Vehicle> getVehicles() {
return m_vehicles;
}
}
Another hibernate entity Object Class called Vehicle for table vehicles with columns
**vehicles
{
id,
vehicleId(primary),
vehicleName
}**
Another table called VehicleDeviceCar with columns
**VehicleDeviceCar
{
vehicleId(Foreign key to vehicles),
devicecarid
}**
**This table doesn't have any primary key.**
Therse is a RESET service servlet written to fetch the deviceinfo as follows
Code:
@Component
@PerRequest
@Scope("prototype")
@Path("deviceInfo")
@Transactional
public class DeviceRestService extends RestService{
@GET
@Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON, MediaType.APPLICATION_ATOM_XML})
public DeviceList getDeviceInfo(){
readLock();
try{
return new DeviceList(m_deviceDao.findAll());
}finally {
readUnlock();
}
}
}
DeviceList class:
Code:
@XmlRootElement(name = "devices")
public class DeviceList extends LinkedList<DeviceInfo> {
private static final long serialVersionUID = 1L;
private int m_totalCount;
public DeviceList() {
super();
}
public DeviceList(Collection<? extends DeviceInfo> c) {
super(c);
}
@XmlElement(name = "device")
public List<DeviceInfo> getDevices() {
return this;
}
public void setDevices(List<DeviceInfo> devices) {
if (devices == this) return;
clear();
addAll(devices);
}
@XmlAttribute(name="count")
public int getCount() {
return this.size();
}
// The property has a getter "" but no setter. For unmarshalling, please define setters.
public void setCount(final int count) {
}
@XmlAttribute(name="totalCount")
public int getTotalCount() {
return m_totalCount;
}
/**
* <p>setTotalCount</p>
*
* @param count a int.
*/
public void setTotalCount(int count) {
m_totalCount = count;
}
}
With the below table data :
deviceinfo
id | devicecarid | status | name
1 | 1234 | true | car1234
2 | 1235 | true | car1235
vehicles
id | vehicleId | vehicleName
1 | V001 | Truck1
VehicleDeviceCar
vehicleId | devicecarid
V001 | 1234
V001 | 1235
When I use the above rest call I can see the output in xml format
Code:
<devices count="1" totalCount="0">
<device devicecarid="1234" id="1" status="true" name="car1234">
<vehicles name="Truck1" id="1" vehicleId="V001"/>
</device>
<device devicecarid="1235" id="2" status="true" name="car1235">
<vehicles name="Truck1" id="1" vehicleId="V001"/>
</device>
</devices>
LazyInitialization exception is thrown when there are duplicates in deviceinfo table e.g.,
deviceinfo
id | devicecarid | status | name
1 | 1234 | true | car1234
2 | 1235 | true | car1235
3 | 1235 | false | car1235
Exception is as follows:
org.hibernate.LazyInitializationException: failed to lazily initialize a collection of role: org.opennms.netmgt.model.OnmsWcru.trains, no session or session was closed
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationException(AbstractPersistentCollection.java:383) ~[hibernate-core-3.6.10.Final.jar:3.6.10.Final]
at org.hibernate.collection.AbstractPersistentCollection.throwLazyInitializationExceptionIfNotConnected(AbstractPersistentCollection.java:375) ~[hibernate-core-3.6.10.Final.jar:3.6.10.Final]
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:368) ~[hibernate-core-3.6.10.Final.jar:3.6.10.Final]
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:111) ~[hibernate-core-3.6.10.Final.jar:3.6.10.Final]
at org.hibernate.collection.PersistentSet.iterator(PersistentSet.java:186) ~[hibernate-core-3.6.10.Final.jar:3.6.10.Final]
Environment:
**JPA 2.0
Hibernate 3.6.10
JDBC 9.1
PostgreSQL 9.2
Java 7**
Could some one please point me in right direction where am I doing wrong ..
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