I have a Generic Repository with a method named saveList(). The purpose of this method is to take a List and persist it in "chunks" of 500 objects. Unfortunately, I'm getting a "TransactionException: Transaction not successfully started" when I get to the commit.
Everything I've seen says that this is a result of the Spring Transaction Manager. Unfortunately, for this particular method, I need to manually control the transaction.
Relevant code is below:
// from generic non-abstract repository
#Transactional
public void saveList(List<T> objectList) {
Session session = sessionFactory.getCurrentSession();
Transaction tx = session.beginTransaction();
int i = 1;
for (T obj : objectList) {
session.save(obj);
//sessionFactory.getCurrentSession().save(obj);
i++;
if (i % 500 == 0) {
session.flush();
//sessionFactory.getCurrentSession().flush();
}
}
if (!tx.wasCommitted()) {
tx.commit();
}
//sessionFactory.getCurrentSession().getTransaction().commit();
}
Configuration from applicationContext.xml:
<tx:annotation-driven transaction-manager="transactionManager" proxy-target-class="true"/>
<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
Any assistance is appreciated.
You're using both declarative and programmatic transaction demarcation. Get rid of the session.beginTransaction() and related method calls. Only use #Transactional.
Use openSession method to get session object and close it when you finished your work. It will work perfectly. For Example
Session session = sessionFactory.openSession();
If you must use a manual transaction, then get rid of the declarative #Transactional option at the top.
I don't really see the point of doing this, since the session is not cleared between the flushes (and will thus need as much memory as if you let Hibernate flush at the end of the transaction), but if you really want to do this, and just want a new transaction just for this method, just annotate the method with
#Transactional(propagation = Propagation.REQUIRES_NEW)
and forget about the Hibernate transaction management.
This will make Spring pause the current transaction (if any), start a new transaction, execute your method and commit/rollback the new transaction, and then resume the paused transaction (if any).
Related
I have Spring 4 with Hibernate 4. My problem is that I want to have transaction on imported data. I parse JSON and next store it to DB. But when something will go wrong (server will go down). I don't want to have part of data in DB.
I have method:
#Transactional
private void processJson()
in which I call in loop:
recipientGroupSellInService.saveOrUpdate(perDay);
it looks much like this:
#Transactional
private void processJson(){
for(int i : iSet){
recipientGroupSellInService.saveOrUpdate(perDay[i]);
}
}
save or update:
#Transactional
public Boolean saveOrUpdate(T model) {
getSession().saveOrUpdate(model);
return true;
}
so after calling saveOrUpdate data is stored to DB, and not roll back on general failure of method processJson.
What should I look after or change to have "real transaction" on method processJson?
The transaction is started in processJson(). Since your saveOrUpdate() is using the regular #Transactional, it will join the previously started transaction.
If there is a problem (i.e. a RuntimeException), anything made by or from processJson() will be rolled back.
Are you claiming that you're seeing behaviour where partial data is written?
Have you configured the PlatformTransactionManager? (either from xml or from Configuration)
Eg:
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"/>
</bean>
I am using Spring and Hibernate in my application and using Spring Transaction.
So I have a service layer with annotation #Transaction on methods and DAO layer having methods for database query.
#Transactional(readOnly = false)
public void get(){
}
The issue is when I want to save an object in the database,then I have to use session.flush() at the end of DAO layer method. Why?
I think if I have annotated #Transaction, then Spring should automatically commit the transaction on completion of the service method.
DAO layer :
public BaseEntity saveEntity(BaseEntity entity) throws Exception {
try {
Session session = sessionFactory.getCurrentSession();
session.saveOrUpdate(entity);
session.flush();
} catch (HibernateException he) {
throw new Exception("Failed to save entity " + entity);
}
return entity;
}
Service layer :
#Transactional(readOnly = false)
public BaseEntity saveEntity(BaseEntity entity) throws Exception {
return dao.saveEntity(entity);
}
spring config :
<context:property-placeholder properties-ref="deployProperties" />
<tx:annotation-driven transaction-manager="transactionManager" />
<!-- Activate Spring Data JPA repository support -->
<jpa:repositories base-package="com" />
<!-- Declare a datasource that has pooling capabilities-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
destroy-method="close"
p:driverClass="${app.jdbc.driverClassName}"
p:jdbcUrl="${app.jdbc.url}"
p:user="${app.jdbc.username}"
p:password="${app.jdbc.password}"
p:acquireIncrement="5"
p:idleConnectionTestPeriod="60"
p:maxPoolSize="100"
p:maxStatements="50"
p:minPoolSize="10" />
<!-- Declare a JPA entityManagerFactory -->
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
p:persistenceXmlLocation="classpath*:META-INF/persistence.xml"
p:persistenceUnitName="hibernatePersistenceUnit"
p:dataSource-ref="dataSource"
p:jpaVendorAdapter-ref="hibernateVendor"/>
<bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean"
p:dataSource-ref="dataSource" p:configLocation="${hibernate.config}"
p:packagesToScan="com" />
<!-- Specify our ORM vendor -->
<bean id="hibernateVendor" class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter"
p:showSql="false"/>
<!-- Declare a transaction manager-->
<bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="entityManagerFactory"/>
Yes, if you have #Transactional for your DAO method then you need not flush the session manually, hibernate will take care of flushing the session as part of committing the transaction if the operations in the method are successful.
Check this link to know on how #Transactional works - Spring - #Transactional - What happens in background?
By default, hibernate stacks its queries so they can be optimized when they are finally executed onto the database.
The whole point of flush is to flush this stack and execute it in your transaction onto the database. Your leaving the "safe" house of the JVM and execute your query on a big strange database.
This is why you can't select something you've just saved without a flush. It's simply not in the database yet.
The meaning of commit is to end the transaction and make changes of the database visible for others. Once commit has been executed there's no return possible anymore.
Frankly I'm not exactly sure if it is a best practice but for normal CRUD operations you should be able to add flush into your DAO layer.
This way you don't need to worry about it into the service layer.
If you want java to optimize your transaction then you'll have to add it into your service layer. But remember that you don't need to solve performance issues when there aren't any! Flushes all over your code into the service layer is not good for the code readability. Keep it simple and stupid ;)
I substituted:
sessionFactory.openSession();
With:
sessionFactory.getCurrentSession();
And I added this configuration for Hibernate:
<property name="hibernate.current_session_context_class">thread</property>
Now I'm getting this error:
failureorg.hibernate.HibernateException: createQuery is not valid without active transaction
Why should I use beginTransaction() and so on, after I use currentTransaction? I don't want to use transactions... so, what should I change?
You used getCurrentSession, not currentTransaction. Transactions are not optional in Hibernate—you must start a transaction.
The configuration you set up resulted in a session being opened for you automatically, but not a transaction within the session.
You can, skip beginning and committing of transactions by spring integration and declaring your transaction as annotation driven
My application is based on Hibernate 3.2 and Spring 2.5. Here is the transaction management related snippet from the application context:
<tx:annotation-driven transaction-manager="txManager"/>
<bean id="txManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
<property name="nestedTransactionAllowed" value="true"/>
</bean>
<bean id="transactionTemplate" classs="org.springframework.transaction.support.TransactionTemplate">
<property name="transactionManager" ref="txManager"/>
</bean>
<bean class="org.springframework.beans.factory.annotation.RequiredAnnotationBeanPostProcessor"/>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="configLocation" value="classpath:/hibernate.cfg.xml"></property>
</bean>
For all the DAO's there are relevant Service class and the transactions are handled there using #Transactional on each method in the service layer. However there is a scenario now that a method in DAO say "parse()" is called from the service layer. In the service layer I specified #Transactional(readOnly=false). This parse method in the DAO calls another method say "save()" in the same DAO which stores a large number of rows (around 5000) in the database. Now the save method is called in a loop from the parse function. Now the issue is that after around 100 calls to the "save" method.. i sometimes get a OutOfMemory Exception or sometimes the program stops responding.
For now these are the changes which I have made to the save method:
Session session = getHibernateTemplate().getSessionFactory().openSession();
Transaction tx = session.beginTransaction();
int counter = 0;
if(books!=null && !books.isEmpty()){
for (Iterator iterator = books.iterator(); iterator
.hasNext();) {
Book book = (Book) iterator.next();
session.save(book);
counter++;
if(counter % 20==0) {
session.flush();
session.clear();
}
}
}
tx.commit();
session.close();
This is the only method in my application where I start a transaction like this and commit it at the end of method. Otherwise I normally just call getHibernateTemplate.save(). I am not sure whether I should perform transaction management for this save method separately in the DAO by placing #Transactional(readOnly=false, PROPOGATION=NEW) on save(), or is this approach okay?
Also I have updated the hibernate.jdbc.batch_size to 20 in the hibernate.cfg configuration file.
Any suggestions?
For the batch insertion with hibernate, the best practice is StatelessSession, it doesn`t cache any states of your entity, you will not encounter OutOfMemory, the code like:
if (books == null || books.isEmpty) {
return;
}
StatelessSession session = getHibernateTemplate().getSessionFactory().openStatelessSession();
Transaction tx = session.beginTransaction();
for (Book each : books) {
session.insert(book);
}
tx.commit();
session.close();
And the Transaction of StatelessSession is independent from the current transaction context.
You only need the bit with flushing and clearing the session. Leave transaction management to Spring. Use sessionFactory.getCurrentSession() to reach the session that Spring has already opened for you. Also, Spring's recent recommmendation is to avoid HibernateTemplate and work directly with Hibernate's API. Inject SessionFactory to your dao-bean.
I would refactor parse in a way it doesn't call save directly but takes some callback from service layer. Service layer would pass its transactional method with save call as this callback.
It may not work exactly as decribed in your case but from this short description this would be something I'd try.
i'm using spring + hibernate. All my HibernateDAO use directly sessionFactory.
I have application layer -> service layer -> DAO layer and all collections is lazly loaded.
So, the problem is that sometime in the application layer(that contains GUI/swing) i load an entity using a service layer method(that contains #Transactional annotation) and i want to use a lazly property of this object, but obviusly the session is already closed.
What is the best way to resolve this trouble?
EDIT
I try to use a MethodInterceptor, my idea is to write an AroundAdvice for all my Entities and use annotation, so for example:
// Custom annotation, say that session is required for this method
#Target(ElementType.METHOD)
#Retention(RetentionPolicy.RUNTIME)
public #interface SessionRequired {
// An AroundAdvice to intercept method calls
public class SessionInterceptor implements MethodInterceptor {
public Object invoke(MethodInvocation mi) throws Throwable {
bool sessionRequired=mi.getMethod().isAnnotationPresent(SessionRequired.class);
// Begin and commit session only if #SessionRequired
if(sessionRequired){
// begin transaction here
}
Object ret=mi.proceed();
if(sessionRequired){
// commit transaction here
}
return ret;
}
}
// An example of entity
#Entity
public class Customer implements Serializable {
#Id
Long id;
#OneToMany
List<Order> orders; // this is a lazy collection
#SessionRequired
public List<Order> getOrders(){
return orders;
}
}
// And finally in application layer...
public void foo(){
// Load customer by id, getCustomer is annotated with #Transactional
// this is a lazy load
Customer customer=customerService.getCustomer(1);
// Get orders, my interceptor open and close the session for me... i hope...
List<Order> orders=customer.getOrders();
// Finally use the orders
}
Do you think can this work?
The problem is, how to register this interceptor for all my entities without do it in xml file?
There is a way to do it with annotation?
Hibernate recently introduced fetch profiles which (in addition to performance tuning) is ideal for solving issues like this. It allows you to (at runtime) choose between different loading and initialization strategies.
http://docs.jboss.org/hibernate/core/3.5/reference/en/html/performance.html#performance-fetching-profiles
Edit (added section on how to set the fetch profile using an interceptor):
Before you get started: Check that fetch profiles actually will work for you. I haven't used them myself and see that they are currently limited to join fetches. Before you waste time on implementing and wiring up the interceptor, try setting the fetch profile manually and see that it actually solves your problem.
There are many ways to setup interceptors in Spring (according to preference), but the most straight-forward way would be to implement a MethodInterceptor (see http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop-api.html#aop-api-advice-around). Let it have a setter for the fetch profile you want and setter for the Hibernate Session factory:
public class FetchProfileInterceptor implements MethodInterceptor {
private SessionFactory sessionFactory;
private String fetchProfile;
... setters ...
public Object invoke(MethodInvocation invocation) throws Throwable {
Session s = sessionFactory.openSession(); // The transaction interceptor has already opened the session, so this returns it.
s.enableFetchProfile(fetchProfile);
try {
return invocation.proceed();
} finally {
s.disableFetchProfile(fetchProfile);
}
}
}
Lastly, enable the interceptor in the Spring config. This can be done in several ways and you probably already have a AOP setup that you can add it to. See http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop.html#aop-schema.
If you're new to AOP, I'd suggest trying the "old" ProxyFactory way first (http://static.springsource.org/spring/docs/3.0.x/spring-framework-reference/html/aop-api.html#aop-api-proxying-intf) because it's easier to understand how it works. Here's some sample XML to get you started:
<bean id="fetchProfileInterceptor" class="x.y.zFetchProfileInterceptor">
<property name="sessionFactory" ref="sessionFactory"/>
<property name="fetchProfile" ref="gui-profile"/>
</bean>
<bean id="businessService" class="x.y.x.BusinessServiceImpl">
<property name="dao" .../>
...
</bean>
<bean id="serviceForSwinGUI"
class="org.springframework.aop.framework.ProxyFactoryBean">
<property name="proxyInterfaces" value="x.y.z.BusinessServiceInterface/>
<property name="target" ref="businessService"/>
<property name="interceptorNames">
<list>
<value>existingTransactionInterceptorBeanName</value>
<value>fetchProfileInterceptor</value>
</list>
</property>
</bean>
Create a method in the service layer that returns the lazy-loaded object for that entity
Change to fetch eager :)
If possible extend your transaction into the application layer
(just while we wait for someone who knows what they are talking about)
You need to rework your session management, unfortunately. This is a major problem when dealing with Hibernate and Spring, and it's a gigantic hassle.
Essentially, what you need is for your application layer to create a new session when it gets your Hibernate object, and to manage that and close the session properly. This stuff is tricky, and non-trivial; one of the best ways to manage this is to mediate the sessions through a factory available from your application layer, but you still need to be able to end the session properly, so you have to be aware of the lifecycle needs of your data.
This stuff is the most common complaint about using Spring and Hibernate in this way; really, the only way to manage it is to get a good handle on exactly what your data lifecycles are.