Spring getCurrentSession() and save sevaral object - spring

Currently, I use openSession(), begin and commit transaction in a method with classic dao and service layers and save/update/delete multiple object in it. If any error exist I am sure that any save/update in this method did not done.
Is it possible to save more than one object in a method called with #Transactional annotation via getCurrentSession() and it is safe if this guarantee that all object in this method saved/updated or any did not done? And if possible how can I use rollback in this method?

Yes you can, with proper transactional semantics.
#Transactional has a property named rollbackFor = TypeOfException.class. By default it rolls back RuntimeException, but you can specify your own or just Exception for any checked exception.
You should have a proper propagation aswell which again you can specify as a property on #Transactional. Note that if you set propagation = REQUIRES_NEW and an existing transaction calls this method, that will rollback for the nested transaction only. What you're trying to achieve, the most common one I think is to specify propagation = REQUIRED - this will not run on its own transaction but proceed on the existing one, which means that on case of failure the whole transaction will rollback.

Related

How make repository save synchronized with Spring Boot

I have one method that first get the last id from my table by one type.
then I set my bean with this number and save
Long number = geradorProtocoloService.getNumero(protocolo.getTipo()
protocolo.setNumber(number);
protocolo = protocoloRepository.saveAndFlush(protocolo);
I put this code in a synchronized block
synchronized (this) {
protocolo.setNumero(geradorProtocoloService.getNumero(protocolo.getTipo());
protocolo = protocoloRepository.saveAndFlush(protocolo);
}
the method have more logic(save a file and etc) then return this to my user
but when I run my tests the he are catching a few times the same number (numero) I think that happens because the jpa don't commit my transaction when I execute saveAndFlush.
So how can I make everything in my synchronizes block be commited with jpa
tks
You are probably right in your analysis.
Normally transactions are controlled by #Transactional annotations. So if you extract your synchronized block in a method in a Spring Bean with a #Transactional annotation and call it from outside any transaction it will commit in the end.

spring transactional nested open session?

If a method of service is marked as #Transactional with propagation nested, and inside it there are many calls to other #Transactional methods, each one of these methods will use its own session? It should represent many connections to db for just one method call no?
It looks like PROPAGATION_REQUIRED is better option for your purpose. From its javadoc:
Support a current transaction; create a new one if none exists.
Refer this link for more details

Do Spring transactions propagate through new instantiations

I'm working on a bunch of legacy code written by people before me and I'm confused about a particular kind of setup and wonder if this has ever worked to begin with.
There is a managed bean in spring that has a transactional method.
#Transactional(propagation = Propagation.REQUIRES_NEW, rollbackFor = Throwable.class)
public boolean updateDraftAndLivePublicationUsingFastDocumentsOfMySite(List<FastDocumentLite> fastDocumentLites, Long mySiteId) throws Exception { ... }
Now inside that method I find new instantiations calling update methods fe:
boolean firstFeed = new MySiteIdUpdate(publishing, siteDao, siteDomainService).update(siteId, fastDocumentLites.get(0).getMySiteId());
From my understanding on IOC this new class isn't managed by spring , it's just a variable in the bean. Now going further inside the update method you see another service gets called.
#Transactional(propagation=Propagation.REQUIRED, rollbackFor=Throwable.class)
public void activateSubdomainForSite(Long siteId, boolean activationOfSite)
So if there is a transaction open it should be propagated into this service. But here is what I don't get if that MySiteIdUpdate object isn't managed by spring does the first transaction move forward to the activateSubdomainForSite method ?? Or is another transaction being opened here. I looked in the logs and I believe it to be the latter but I rather ask the experts for a second oppinion before I proclame this legacy code to be complete rubbish to the project lead. I'm suffering with a StaleStateException somewhere further down the road and I'm hoping this has anything to do with it.
I think the code is correct, and the second #Transactional should reuse the existing transaction.
Because:
1) Spring Transaction handling is done either by Proxies or by AspectJ advices. If it is done by Proxies then it is required that MySiteIdUpdate invoke an instance that is injected (this is what you did). If you use AspectJ, then it should work anyway.
2) The association Transactions to the code that use is done by the Thread, this mean, as long as you "are" in the thread which started the transaction you can use it. (you do not start an new thread, so it should work)
An other way to explain: It is perfect legal when you have some method in your call hierarchy that does not belong to an spring bean. This should not make the transaction handling fail.

Spring transaction propagation_required issue

In our java project we are using ORM with hibernate and spring.
I had problems in deleting persistent objects. For example this sample method gets entities by ids and then delete them:
#Transactional
public void remove(List<Long> ids) {
SearchTemplate template = new SearchTemplate();
template.addParameter("milestoneId",ids);
List <InvoiceQueue> items = this.findByCriteria(template);
...
this.delete(items);
}
Method executes Ok without any exception but doesn't actually delete the items from the DB.
Adding the following annotation to the method definition #Transactional(propagation = Propagation.REQUIRES_NEW) solves the problem.
Can anyone explain why it doesn't work with the default propagation type PROPAGATION_REQUIRED.
Thanks in advance.
Environment details :
hibernate.version 3.5.5-Final, spring.version 3.0.5.RELEASE
Really just repeating what #PeterBagyinszki said in his comment, but the reason quite probably is that the transaction within which your delete occurs gets rolled back due to some other part throwing an exception, and all the changes made during the transaction get canceled. With Propagation.REQUIRES_NEW, the delete is done within it's own separate nested transaction. The outcome of the nested transaction (committed or rolled back) won't affect the "outer" transaction and vice versa.
Check your logs to see what is causing the transaction to be rolled back, note that even something like a simple SELECT -query failing with something like NoResultException will cause the transaction to roll back, unless you explicitly state in the #Transactional-annotation it not to roll back on certain exceptions.

#Transactional Annotation + for a data insertion in a loop

I am using Spring 3, JPA + Hibernate for a CMS application. In that application I have a service class method which is annotated with #Transactional Annotation with rollBack property. Inside that method I am inserting data (ie entity classes) to a table using a loop. For each iteration of the loop entity classes has to be saved to the database. But it is not happening. The commit only happens when the execution of the loop has completed and exits from the method. Then it commits and saves all at once. But I need to read data once it gets inserted into the database before committing in this case. I tried with the ISOLATION LEVEL to read uncommitted but it didn't supported since I am using the default JPADialect. Also tried to add the hibernate implementation of jpaDialect but still it didn't worked. Please help with a workaround for this problem. One more thing, is there any way using propagation required method.
You are right, this is what I stands for in acid. Because the transactions are working in isolation, other transactions cannot see them before they are committed. But playing with isolation levels is a bad practice. I would rather advice you to run each and every iteration in a separate transaction with start and commit inside.
This is a bit tricky in Spring, but here is an example:
public void batch() {
for(...) {
insert(...)
}
}
//necessarily in a different class!
#Transactional
public void insert() {
}
Note that batch() is not annotated with #Transactional and insert() has to be in a different class (Spring service). Too long to comment, but that's life. If you don't like it, you can use TransactionTemplate manually.
remove the transactional annoation on the the method with loop.
In the loop call a separate method to perform the save, make that method transactional
You either need to go with programmatic transactions (Spring's TransactionTemplate or PlatformTransactionManager are the classes to look at, see Spring Doc for programmatic transactions, or you can call another transactional method from within your loop where the transaction is marked with Propagation.REQUIRES_NEW, meaning each call of that method is executed in its own transaction, see here. I think that the second approach requires you to define the REQUIRES_NEW method on a different Spring bean because of the AOP-Proxy. You can also omit the REQUIRES_NEW if the loop is not executed within a transaction.

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