session closing while using HibernateTemplate - spring

Consider following code:
public class UserDAOImpl implements UserDAO {
private HibernateTemplate hibernateTemplate;
public void setSessionFactory(SessionFactory sessionFactory){
this.hibernateTemplate = new HibernateTemplate(sessionFactory);
}
public void saveUser(User user) {
hibernateTemplate.saveOrUpdate(user);
}
public void deleteUser(User user) {
hibernateTemplate.delete(user);
}
}
One of the main task of HibernateTemplate is to open and close the session transparently.
In above code there are two methods saveUser() and deleteUser().I want to ask:
1)Will HibernateTemplate create two separate sessions for these two methods and when the closing/flushing of session takes place in this case.
2)Is it same like spring transactions, as in spring, transactions are adviced around method calls and opening, closing of session happens at method/transaction boundaries?

Default flush mode is FlushMode.AUTO. Look at the links below. I think it will answer your questions.
http://static.springsource.org/spring/docs/1.2.9/api/org/springframework/orm/hibernate3/HibernateAccessor.html#setFlushMode(int)
http://docs.jboss.org/hibernate/orm/3.5/api/org/hibernate/FlushMode.html

Related

Spring JPA: javax.persistence.TransactionRequiredException: no transaction is in progress [duplicate]

I am new to Spring Transaction. Something that I found really odd, probably I did understand this properly.
I wanted to have a transactional around method level and I have a caller method within the same class and it seems like it does not like that, it has to be called from the separate class. I don't understand how is that possible.
If anyone has an idea how to resolve this issue, I would greatly appreciate. I would like to use the same class to call the annotated transactional method.
Here is the code:
public class UserService {
#Transactional
public boolean addUser(String userName, String password) {
try {
// call DAO layer and adds to database.
} catch (Throwable e) {
TransactionAspectSupport.currentTransactionStatus()
.setRollbackOnly();
}
}
public boolean addUsers(List<User> users) {
for (User user : users) {
addUser(user.getUserName, user.getPassword);
}
}
}
It's a limitation of Spring AOP (dynamic objects and cglib).
If you configure Spring to use AspectJ to handle the transactions, your code will work.
The simple and probably best alternative is to refactor your code. For example one class that handles users and one that process each user. Then default transaction handling with Spring AOP will work.
Configuration tips for handling transactions with AspectJ
To enable Spring to use AspectJ for transactions, you must set the mode to AspectJ:
<tx:annotation-driven mode="aspectj"/>
If you're using Spring with an older version than 3.0, you must also add this to your Spring configuration:
<bean class="org.springframework.transaction.aspectj
.AnnotationTransactionAspect" factory-method="aspectOf">
<property name="transactionManager" ref="transactionManager" />
</bean>
In Java 8+ there's another possibility, which I prefer for the reasons given below:
#Service
public class UserService {
#Autowired
private TransactionHandler transactionHandler;
public boolean addUsers(List<User> users) {
for (User user : users) {
transactionHandler.runInTransaction(() -> addUser(user.getUsername, user.getPassword));
}
}
private boolean addUser(String username, String password) {
// TODO call userRepository
}
}
#Service
public class TransactionHandler {
#Transactional(propagation = Propagation.REQUIRED)
public <T> T runInTransaction(Supplier<T> supplier) {
return supplier.get();
}
#Transactional(propagation = Propagation.REQUIRES_NEW)
public <T> T runInNewTransaction(Supplier<T> supplier) {
return supplier.get();
}
}
This approach has the following advantages:
It may be applied to private methods. So you don't have to break encapsulation by making a method public just to satisfy Spring limitations.
Same method may be called within different transaction propagations and it is up to the caller to choose the suitable one. Compare these 2 lines:
transactionHandler.runInTransaction(() -> userService.addUser(user.getUserName, user.getPassword));
transactionHandler.runInNewTransaction(() -> userService.addUser(user.getUserName, user.getPassword));
It is explicit, thus more readable.
The problem here is, that Spring's AOP proxies don't extend but rather wrap your service instance to intercept calls. This has the effect, that any call to "this" from within your service instance is directly invoked on that instance and cannot be intercepted by the wrapping proxy (the proxy is not even aware of any such call). One solutions is already mentioned. Another nifty one would be to simply have Spring inject an instance of the service into the service itself, and call your method on the injected instance, which will be the proxy that handles your transactions. But be aware, that this may have bad side effects too, if your service bean is not a singleton:
<bean id="userService" class="your.package.UserService">
<property name="self" ref="userService" />
...
</bean>
public class UserService {
private UserService self;
public void setSelf(UserService self) {
this.self = self;
}
#Transactional
public boolean addUser(String userName, String password) {
try {
// call DAO layer and adds to database.
} catch (Throwable e) {
TransactionAspectSupport.currentTransactionStatus()
.setRollbackOnly();
}
}
public boolean addUsers(List<User> users) {
for (User user : users) {
self.addUser(user.getUserName, user.getPassword);
}
}
}
With Spring 4 it's possible to Self autowired
#Service
#Transactional
public class UserServiceImpl implements UserService{
#Autowired
private UserRepository repository;
#Autowired
private UserService userService;
#Override
public void update(int id){
repository.findOne(id).setName("ddd");
}
#Override
public void save(Users user) {
repository.save(user);
userService.update(1);
}
}
This is my solution for self invocation:
public class SBMWSBL {
private SBMWSBL self;
#Autowired
private ApplicationContext applicationContext;
#PostConstruct
public void postContruct(){
self = applicationContext.getBean(SBMWSBL.class);
}
// ...
}
You can autowired BeanFactory inside the same class and do a
getBean(YourClazz.class)
It will automatically proxify your class and take into account your #Transactional or other aop annotation.
Here is what I do for small projects with only marginal usage of method calls within the same class. In-code documentation is strongly advised, as it may look strange to colleagues. But it works with singletons, is easy to test, simple, quick to achieve and spares me the full blown AspectJ instrumentation. However, for more heavy usage I'd advice the AspectJ solution as described in Espens answer.
#Service
#Scope(proxyMode = ScopedProxyMode.TARGET_CLASS)
class PersonDao {
private final PersonDao _personDao;
#Autowired
public PersonDao(PersonDao personDao) {
_personDao = personDao;
}
#Transactional
public void addUser(String username, String password) {
// call database layer
}
public void addUsers(List<User> users) {
for (User user : users) {
_personDao.addUser(user.getUserName, user.getPassword);
}
}
}
The issue is related to how spring load classes and proxies. It will not work , untill you write your inner method / transaction in another class or go to other class and then again come to your class and then write the inner nested transcation method.
To summarize, spring proxies does not allow the scenarios which you are facing. you have to write the 2nd transaction method in other class
There is no point to use AspectJ or Other ways. Just using AOP is sufficient. So, we can add #Transactional to addUsers(List<User> users) to solve current issue.
public class UserService {
private boolean addUser(String userName, String password) {
try {
// call DAO layer and adds to database.
} catch (Throwable e) {
TransactionAspectSupport.currentTransactionStatus()
.setRollbackOnly();
}
}
#Transactional
public boolean addUsers(List<User> users) {
for (User user : users) {
addUser(user.getUserName, user.getPassword);
}
}
}

Spring cloud stream : how to use #Transactional with new Consumer<> functional programming model

I have StreamListener which I would like to replace using the new functional model and Consumer <>. Unfortunately, I don't know how to transfer #Transactional to new model:
#Transactional
#StreamListener(PaymentChannels.PENDING_PAYMENTS_INPUT)
public void executePayments(PendingPaymentEvent event) throws Exception {
paymentsService.triggerInvoicePayment(event.getInvoiceId());
}
I have tired certain things. Sample code below. I added logging messages to a different queue for tests. Then I throw an exception to trigger a rollback. Unfortunately, messages are queued even though they are not there until the method is completed (I tested this using brakepoints). It seems that the transaction was automatically committed despite the error.
#Transactional
#RequiredArgsConstructor
#Component
public class functionalPayment implements Consumer<PendingPaymentEvent> {
private final PaymentsService paymentsService;
private final StreamBridge streamBridge;
public void accept(PendingPaymentEvent event) {
paymentsService.triggerInvoicePayment(event.getInvoiceId());
streamBridge.send("log-out-0",event);
throw new RuntimeException("Test exception to rollback message from log-out-0");
}
}
Configuration:
spring.cloud.stream.rabbit.bindings.functionalPayment-in-0.consumer.queue-name-group-only=true
spring.cloud.stream.rabbit.bindings.functionalPayment-in-0.consumer.declare-exchange=true
spring.cloud.stream.rabbit.bindings.functionalPayment-in-0.consumer.bind-queue=true
spring.cloud.stream.rabbit.bindings.functionalPayment-in-0.consumer.transacted=true
spring.cloud.stream.source=log
spring.cloud.stream.bindings.log-out-0.content-type=application/json
spring.cloud.stream.bindings.log-out-0.destination=log_a
spring.cloud.stream.bindings.log-out-0.group=log_a
spring.cloud.stream.rabbit.bindings.log-out-0.producer.declare-exchange=true
spring.cloud.stream.rabbit.bindings.log-out-0.producer.bind-queue=true
spring.cloud.stream.rabbit.bindings.log-out-0.producer.queue-name-group-only=true
spring.cloud.stream.rabbit.bindings.log-out-0.producer.binding-routing-key=log
spring.cloud.stream.rabbit.bindings.log-out-0.producer.transacted=true
spring.cloud.stream.rabbit.bindings.log-out-0.producer.exchange-type=direct
spring.cloud.stream.rabbit.bindings.log-out-0.producer.routing-key-expression='log'
Have you tried something along the lines of
#Transactional
public class ExecutePaymentConsumer implements Consumer<PendingPaymentEvent> {
public void accept(PendingPaymentEvent event) {
paymentsService.triggerInvoicePayment(event.getInvoiceId());
}
}
. . .
#Bean
public ExecutePaymentConsumer executePayments() {
return new ExecutePaymentConsumer();
}

Do I need I need to close SqlSession which create by SqlSessionFactory in Service?

I want to to batch add user's role info, so i get mapper from sqlSessionFactory, so do I need to close the SqlSession after I used it?I don't know whether Spring will help me close the SqlSession.
public interface UserService{
void insertRoleRelation(Long userId,List<Long> roleIdList);
}
#Service
public class UserServiceImpl implements UserService{
#Autowired
private SqlSessionFactory sqlSessionFactory;
#Override
public void insertRoleRelation(Long userId,List<Long> roleIdList) {
SqlSession sqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH);
UserRoleRelationMapper sessionUserRoleRelationMapper = sqlSession.getMapper(UserRoleRelationMapper.class);
if (!CollectionUtils.isEmpty(roleIdList)) {
roleIdList.forEach(i -> {
//insert role relation
});
}
sqlSession.flushStatements();
//do I need to close sqlSession here?
//sqlSession.close()
}
}
Thanks for ave's comment,I find the easyest way to execute batch insert.you can see this article:
how to use mybatis effectively perform batch db operations

How to involve a Collection on a spring transaction?

I currently have a spring application with hibernate and a PlataformTransactionManager running on Jboss/wildfly.
Some of the methods that manipulate the database also call a bean which contains a LinkedBlockingQueue. This queue stores logging messages that are periodically dispatched to someplace else on another thread (using simple spring #Scheduler).
Would it be possible to make my queue (inside a bean) transactional? ie. if the transaction rollback would I be able to "undo" any operations made on my Collection? What's the best strategy to implement this ?
So, in short something like:
#Service
#Transactional
public PersonService {
#Autowired
EntityManager EM;
#Autowired
LoggingBuffer logger;
public void addPerson(String name) {
EM.persist(new Person(.....));
logger.add("New person!");
// A rollback here via some thrown exception would not affect the queue
}
}
#Component
public class LoggingBuffer {
private Queue<String> q= new LinkedBlockingQueue<String>();
public add(String msg){
q.add(msg);
}
}
Try something like this
#Transactional
public void addPerson(String name) {
EM.persist(new Person(.....));
//logger.add("New person!");
// A rollback here via some thrown exception would not affect the queue
}
public void wrapAddPerson(String name){
List<String> localBuffer = new ArrayList<>();
try{
addPerson(name);
localBuffer.add(".....");
}catch(Exception e)
{
localBuffer.clear();
}
finally{
localBuffer.forEach(logger::add);
}
}

Wipe InProcess Neo4j DB after each test

I'm using Spring with a Test-Configuration that gives my an InProcessServer Neo4j Database that i use for testing.
Sadly, after each #Test method, there is still scrap-data in this database.
Is it possible to wipe this DB after each Test-Method?
You can inject the Session and use purgeDatabase() to delete everything from the database-
#Autowired
private Session session;
#After
public void clear() {
session.purgeDatabase();
}
Your config that extends Neo4jConfiguration should have
#Override
#Bean
public Session getSession() throws Exception {
return super.getSession();
}

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