I have a two entity classes where i have hibernate many to one mapping. But when one of the class (QueryEntity) is fetched, the one to many collection Set lookUpCols (of class LookUpCols) is not getting loaded even though its fetch type is eager. I am getting queryEntity.getLookUpCols().size() = 0. In the back end, the HQL Query is generating as expected. Both the main entity and the eager entity query are being fired, but the object is not getting loaded.Can any one suggest why this is happening.
QueryEntity.java
package entity;
import java.util.Date;
import java.util.Set;
public class QueryEntity {
Long queryId;
ColumnMeta queryColumnMeta;
QueryType queryType;
String paramNames;
String mainQuery;
Date lastUpdtTS;
public Set < LookUpCols > lookUpCols;
String queryName;
//getters and setters
}QueryEntity.hbm.xml
<hibernate-mapping>
<class name="entity.QueryEntity" table="QueryEntity">
<meta attribute="class-description">
</meta>
<id name="queryId" type="long" column="queryId">
<generator class="increment" />
</id>
<property name="paramNames" column="paramNames" type="string" />
<property name="mainQuery" column="mainQuery" type="string" />
<property name="queryName" column="queryName" type="string" />
<many-to-one name="queryColumnMeta" column="queryColumnMeta" class="entity.ColumnMeta" />
<set name="lookUpCols" table="LookUpCols" inverse="false" lazy="false" cascade="all" fetch="join">
<key>
<column name="queryId" />
</key>
<one-to-many class="entity.LookUpCols" />
</set>
<property name="queryType" column="queryType">
<type name="org.hibernate.type.EnumType">
<param name="enumClass">entity.QueryType</param>
<param name="useNamed">true</param>
</type>
</property>
</class>
</hibernate-mapping>LookUpCols.java
package entity;
import java.util.Date;
public class LookUpCols {
Long lookUpId;
QueryEntity query;
String lookUpColName;
String lookUpQuery;
Date lastUpdtTS;
// getters and setters
}
LookUpCols.hbm.xml
<hibernate-mapping>
<class name="entity.LookUpCols" table="LookUpCols">
<meta attribute="class-description">
</meta>
<id name="lookUpId" type="long" column="lookUpId">
<generator class="increment" />
</id>
<many-to-one name="query" column="query" class="entity.QueryEntity" fetch="select" not-null="true" />
<property name="lookUpColName" column="lookUpColName" type="string" />
<property name="lookUpQuery" column="lookUpQuery" type="string" />
<property name="lastUpdtTS" column="lastUpdtTS" type="date" />
</class>
</hibernate-mapping>HQL QUeries
Hibernate:
select
queryentit0_.queryId as queryId104_,
queryentit0_.paramNames as paramNames104_,
queryentit0_.mainQuery as mainQuery104_,
queryentit0_.queryName as queryName104_,
queryentit0_.queryColumnMeta as queryCol5_104_,
queryentit0_.queryType as queryType104_
from
QueryEntity queryentit0_
Hibernate:
select
lookupcols0_.queryId as queryId104_1_,
lookupcols0_.lookUpId as lookUpId1_,
lookupcols0_.lookUpId as lookUpId102_0_,
lookupcols0_.query as query102_0_,
lookupcols0_.lookUpColName as lookUpCo3_102_0_,
lookupcols0_.lookUpQuery as lookUpQu4_102_0_,
lookupcols0_.lastUpdtTS as lastUpdtTS102_0_
from
LookUpCols lookupcols0_
where
lookupcols0_.queryId = ?Adding the code that runs fetches the Entity. This is the generic function that i call to read all data. I pass the class name (in this case QueryEntity) to this function which in turn fetches the data.
GenericDAOImpl.java
package daoImpl;
import java.io.File;
import java.io.Serializable;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityTransaction;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;
import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import dao.GenericDAO;
import exceptions.EntityNotPresent;
public class GenericDAOImpl<T, ID extends Serializable> implements GenericDAO<T, ID> {
SessionFactory factory;
public GenericDAOImpl() {
super();
Configuration cfg = new Configuration();
File f = new File(
"path to my persistence.xml");
cfg.configure(f);
factory = cfg.buildSessionFactory();
}
@Override
public T save(T t) {
Session session = factory.openSession();
session.beginTransaction().begin();
session.persist(t);
session.flush();
session.beginTransaction().commit();
session.close();
return t;
}
// This is the generic function that i call to read all data. I pass
// the class name (in this case QueryEntity) to this function which in turn fetches the data.
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public List<T> readAll(Class clazz) {
Session session = factory.openSession();
session.beginTransaction().begin();
Query query = session.createQuery("from " + clazz.getName());
List<T> listT = query.list();
session.beginTransaction().commit();
session.close();
return listT;
}
@SuppressWarnings("unchecked")
@Override
public T readById(@SuppressWarnings("rawtypes") Class clazz, ID id) {
/*
* entityTransaction.begin(); T t = (T) entityManager.find(clazz, id);
* entityTransaction.commit(); return t;
*/
Session session = factory.openSession();
session.beginTransaction().begin();
T t = null;
t = (T) session.load(clazz, id);
session.beginTransaction().commit();
session.close();
return t;
}
@Override
public void delete(@SuppressWarnings("rawtypes") Class clazz, ID removeId) {
if (isEntityExists(clazz, removeId)) {
T old = readById(clazz, removeId);
entityTransaction.begin();
entityManager.remove(old);
entityTransaction.commit();
}
}
@SuppressWarnings("unchecked")
@Override
public boolean isEntityExists(@SuppressWarnings("rawtypes") Class clazz, ID id) {
return entityManager.find(clazz, id) != null;
}
@SuppressWarnings("unchecked")
@Override
public T getFirstRecord(Class<?> clazz) {
entityTransaction.begin();
Session session = entityManager.unwrap(Session.class);
Criteria queryCriteria = session.createCriteria(clazz);
queryCriteria.setFirstResult(0);
queryCriteria.setMaxResults(1);
T t = (T) queryCriteria.list().get(0);
entityTransaction.commit();
return t;
}
@Override
public List<T> getByQuery(String queryExecute, Object[] pars, @SuppressWarnings("rawtypes") Class clazz) {
entityTransaction.begin();
@SuppressWarnings("unchecked")
TypedQuery<T> query = entityManager.createQuery(queryExecute, clazz);
for (int i = 0; i < pars.length; i++) {
query.setParameter("arg" + i, pars[i]);
}
List<T> results = query.getResultList();
entityTransaction.commit();
return results;
}
@Override
public T update(@SuppressWarnings("rawtypes") Class clazz, ID id, T t) throws EntityNotPresent {
return null;
}
}
So the query is correctly executing, but the collection is not getting loaded. Please help
