Batch insertion with Spring MVC and Hibernate 3 - spring

Question

I am using Spring MVC + Hibernate and try to save bulk record using "hibernate batch procession technique" but getting below exception when I am doing session.flush() and session.clear().
org.hibernate.LazyInitializationException: could not initialize proxy - no Session
following is my code sample
DaoImpl method
#SuppressWarnings("unchecked")
#Override
public String transferPsalesDataToMisSales() {
Session session = null;
Transaction tx=null;
String result="failed";
try {session = this.getSessionFactory().openSession();
tx = session.beginTransaction();
Criteria criteria=session.createCriteria(PsalesInfo.class);
List<PsalesInfo> pSalesData=criteria.list();
if(pSalesData.size() >0){
Iterator<PsalesInfo> it=pSalesData.iterator();
int index=0;
MisSalesInfo mis=null;
while(it.hasNext()){
mis=new MisSalesInfo();
PsalesInfo psales=it.next();
StockistInfo stockistInfo=psales.getStockistInfo();
TalukaInfo talukaInfo=stockistInfo.getTalukaInfo();
IsrInfo isr=(IsrInfo) session.get(IsrInfo.class, stockistInfo.getIsrId());
//mis settters
mis.setMisSalesId(psales.getPsalesId());
mis.setStateName(talukaInfo.getDistrictInfo().getStateInfo().getStateName());
mis.setDistName(talukaInfo.getDistrictInfo().getDistName());
mis.setTalukaName(talukaInfo.getTalukaName());
mis.setAsmId(talukaInfo.getAsmInfo().getAsmId());
mis.setTsoId(stockistInfo.getTsoInfo().getTsoId());
if(null!=isr){
mis.setIsrId(isr.getIsrId());
mis.setIsrName(isr.getIsrName());
}
mis.setUnitNo(stockistInfo.getUnitNo());
mis.setBillNo(psales.getBillNo());
session.save(mis);
if(index % 50==0){
//flush a batch of inserts and release memory:
session.flush();
session.clear();
}
index++;
}//end of while
tx.commit();
result=pSalesData.size()+" Psales are Successfully transfered to MIS Sales";
}
else{
result="No Psales is available to transfer since are already available in MIS Sales";
}
} catch (HibernateException e) {
tx.rollback();
logger.error("error in MasterDaoImpl transfer data:"+e);
}finally {
if (null != session)
session.close();
}
return result;
}
POJOs
#Entity
#Table(name = "psales_info", catalog = "secondary_sales")
public class PsalesInfo implements java.io.Serializable {
private static final long serialVersionUID = 5578632011679493005L;
private Integer psalesId;
private StockistInfo stockistInfo;
//and some other attributes
//getter and setters
#Id
#GenericGenerator(name="generator", strategy="increment")
#GeneratedValue(generator="generator")
#Column(name = "psales_id", unique = true, nullable = false)
public Integer getPsalesId() {
return this.psalesId;
}
public void setPsalesId(Integer psalesId) {
this.psalesId = psalesId;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "pcode", nullable = false)
public StockistInfo getStockistInfo() {
return this.stockistInfo;
}
//and others
#Entity
#Table(name = "stockist_info", catalog = "secondary_sales")
public class StockistInfo implements java.io.Serializable {
private String stockistId;
private TalukaInfo talukaInfo;
//and rest attributes
//getters and setters
// Property accessors
#Id
#Column(name = "stockist_id", unique = true, nullable = false, length = 10)
public String getStockistId() {
return this.stockistId;
}
public void setStockistId(String stockistId) {
this.stockistId = stockistId;
}
#ManyToOne(fetch = FetchType.LAZY)
#JoinColumn(name = "taluka_sid", nullable = false)
public TalukaInfo getTalukaInfo() {
return this.talukaInfo;
}
ServiceImpl
#Service
#Transactional
public class TransactionServiceImpl implements TransactionService {
#Autowired
private TransactionDAO transactionDAO;
#Override
public String transferPsalesDataToMisSales() {
return this.getTransactionDAO().transferPsalesDataToMisSales();
}
}
dispature-servlet.xml
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource" ref="dataSource"></property>
<property name="configLocation" value="classpath:hibernate.cfg.xml"/>
<property name="configurationClass" value="org.hibernate.cfg.AnnotationConfiguration"/>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">${hibernate.dialect}</prop>
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
<prop key="hibernate.hbm2ddl.auto">${hibernate.hbm2ddl.auto}</prop>
<prop key="hibernate.default_catalog">${hibernate.default_catalog}</prop>
<prop key="hibernate.jdbc.batch_size">50</prop>
</props>
</property>
</bean>
<tx:annotation-driven transaction-manager="transactionManager"/>
<bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager"
p:sessionFactory-ref="sessionFactory"/>
Need help here why it is throwing LazyInitializationException when I'm clearing the session.
But when I'm not clearing the session ie. wihtout session.clear() and session.flush() application is running properly.
but I know it may lead to OutOfMemoryException in case of more bulk record.
so plz tell how to deal with this situation now?

Answer 1

Your dao code is flawed... Don't open new sessions yourself and don't mess aroudn with transactions yourself either. Remove the transaction stuff from your dao method and the call to openSession should be replaced with getCurrentSession.
#SuppressWarnings("unchecked")
#Override
public String transferPsalesDataToMisSales() {
Session session = this.getSessionFactory().getCurrentSession();
Criteria criteria=session.createCriteria(PsalesInfo.class);
List<PsalesInfo> pSalesData=criteria.list();
int index=0;
for (PsalesInfo psales : pSalesData) {
MisSalesInfo mis=new MisSalesInfo();
StockistInfo stockistInfo=psales.getStockistInfo();
TalukaInfo talukaInfo=stockistInfo.getTalukaInfo();
IsrInfo isr=(IsrInfo) session.get(IsrInfo.class, stockistInfo.getIsrId());
//mis settters
mis.setMisSalesId(psales.getPsalesId());
mis.setStateName(talukaInfo.getDistrictInfo().getStateInfo().getStateName());
mis.setDistName(talukaInfo.getDistrictInfo().getDistName());
mis.setTalukaName(talukaInfo.getTalukaName());
mis.setAsmId(talukaInfo.getAsmInfo().getAsmId());
mis.setTsoId(stockistInfo.getTsoInfo().getTsoId());
if(null!=isr){
mis.setIsrId(isr.getIsrId());
mis.setIsrName(isr.getIsrName());
}
mis.setUnitNo(stockistInfo.getUnitNo());
mis.setBillNo(psales.getBillNo());
session.save(mis);
if(index % 50==0){
//flush a batch of inserts and release memory:
session.flush();
session.clear();
}
index++;
}//end of loop
if (pSalesData.isEmpty() ) {
return "No Psales is available to transfer since are already available in MIS Sales";
} else {
return pSalesData.size()+" Psales are Successfully transfered to MIS Sales";
}
}