We're using Spring 3.1, JPA (via Hibernate) and Quartz. Typically we interact with the DB via #PersistenceContext annotation on Service beans, and either SpringMVC controllers, or GraniteDS-managed service invocation.
I'm working on writing a Quartz job that needs to interact with the database. I've tried everything I can find to get this working. I tried passing in a Spring-managed component (annotated with #PersistenceContext and #Transactional) via the jobMap, the call to entityManager.persist(o) executes, but nothing happens in the database. I also tried similar to this answer, creating a factory class to call autowireBean() on the job object. I set up the job class like so:
public class CreateAlertJob implements Job {
#PersistenceContext
EntityManager entityManager;
#Override
#Transactional
public void execute(JobExecutionContext context) throws JobExecutionException {
SomeEntity entity = new SomeEntity();
entityManager.persist(entity);
}
}
Same result, the method executes but the database is unaltered. I found this blog post which references a GitHub project. There he is using JpaInterceptor to establish a Hibernate session, but this uses the DAO pattern and I'd like to stick with using #PersistenceContext.
Clearly there is something about the Quartz thread that is preventing this from working properly? I'm about out of ideas and considering making a web service call to a SpringMVC controller just to get this working.
Since your CreateAlertJob is not created by Spring, #Transactional in it doesn't take effect.
You have the following options:
Delegate actual work to Spring bean and put #Transactional there
Use programmatic transaction management
Use AspectJ-based AOP implementation instead of Spring default implementation (but it would be overkill for such a simple problem)
Related
SpringBoot Application with SpringBatch and JPA, without #Async all working fine but with #Async added in the REST API the job is completed but JPAItemWriter is not persisting the objects in the DB. looks like Transactional problem as am getting this exception.
Transaction Manager [org.sringframework.batch.support.transaction.ResourcelessTransactionManager] does not support transaction suspension.
I tried with different approaches like changing Propagation.Requires_New (Required, Supports) but nothing works, tried searching all the forums but no luck.
#Service
public class SampleWriter extends JpaItemWriter<TestEntity> {
#Autowired
EntityManager entityManager;
#Transactional(readOnly=false, propagation = Propagation.REQUIRED, isolation = Isolation.READ_COMMITTED)
#Override
public void write(List<TestEntity> entities) {
this.doWrite(entityManager, entities);
}
}
It seems that you are configuring and using Spring Batch in a wrong way.
Firstly, it is using the default BatchConfigurer which the TransactionManager is ResourcelessTransactionManager that is mainly use for testing or acts as a "no-op" TransactionManager for the batch job that does not require any transaction which is definitely not your case now.
Secondly, Spring Batch will internally take care of managing the transaction boundary for processing each chunk , you do not need to extend JpaItemWriter and control the transaction behaviour using #Transactional by yourself.
So , read this section for how to configure Spring Batch , especially the part related to BatchConfigurer
On the other hand if you are using Spring-boot , it should already configure a JpaBatchConfigurer for you.
I have set transaction timeout in my application as #Transactional(propagation=Propagation.REQUIRED,timeout=30)
ActiveMQXAConnectionFactory and Oracle XA Datasource are two resources of my Distributed transaction. after reading a message from queue my transaction begins and while processing the application is taking more than 30 seconds and still transaction is not timed out. Only when committing the transaction its throwing timeout exception. I wanted immediately after 30 seconds the transaction should time out and throw the exception and make that thread available to consume another message from queue. Is this possible?
Without seeing your configuration it will be hard to say. If you are just adding an #Transactional, it is not going to do anything. You going to need both an EntityManager and a TransactionManager, then you need to turn on annotation based transaction management, and Spring needs to be controlling your datasource if I recall correctly.
Another, probably unnecessary side note, #Transactional will only work on public methods. Spring will proxy your method in order to manage the transaction and Spring can only proxy public methods. Also, it will only be able to work on calls from another class to that method, if you are calling that method from another method inside the same class, Spring cannot proxy either, thus no transaction management. Spring is sneakily deceptive here.
#Service
public class A{
#Autowired
Datasource datasource;
#Transactional
public void save(){
datasource.doStuff();
}
public void callSave(){
save();
}
}
#Service
public class B{
#Autowired
A a;
public void callSave(){
a.save();
}
}
Here, if a.save() is called from a.callSave(), no proxy will occur, thus you will have no transaction management. But in the exact same application, if you call b.callSave(), you will have transaction management, since Spring can then proxy the method call to a.save().
Are you using Spring Boot or vanilla Spring? We can probably give you more of a direction if you divulge that.
Hopefully that helped a bit!
In Spring, I can inject an javax.persistence.EntityManager
into a Spring bean using the annotation #javax.persistence.PersistenceContext, like this:
#Service
public class MyRepository {
#PersistenceContext
private EntityManager entityManager;
}
This is documented in the Spring docs in chapter 20.5.2 Implementing DAOs based on plain JPA.
Is there a way to do this using CDI (specifically, Weld) if I am not using a Java EE container?
In particular, is it possible to reuse the annotation #PersistenceContext for CDI (because existing code uses it with Spring) ?
As far as I understand: When using a Java EE container, the container will interpret the annotation and inject an EntityManager. Is that correct? And is there a way to get this to work using Weld, but without a Java EE container?
I tried to inject the class above into another class using Weld (in Tomcat, without Java EE). The injection takes place, so Weld correctly creates an instance of MyRepository, however the field MyRepository.entityManager is null, as if the annotation #PersistenceContext was ignored.
What is happening (or rather, not happening) here?
You can do it this way:
create Entity Manager Factory Producer
public class EntityManagerFactoryProducer {
#Produces
#ApplicationScoped
public EntityManagerFactory create() {
return Persistence.createEntityManagerFactory("PU");
}
public void destroy(#Disposes EntityManagerFactory factory) {
factory.close();
}
}
and create Entity Manager Producer
public class EntityManagerProducer {
#Inject
transient EntityManagerFactory emf;
#Produces
#RequestScoped
public EntityManager create() {
return emf.createEntityManager();
}
public void destroy(#Disposes EntityManager em) {
em.close();
}
}
then you can use dependency injection (CDI will create one em for each request)
#Inject
EntityManager entityManager;
You have to start the CDI context in your main method
public static void main(String[] args) throws IOException {
Weld weld = new Weld();
WeldContainer container = weld.initialize();
Application application = container.instance().select(Application.class).get();
application.run();
weld.shutdown();
}
ps. If you have more then one PU use #Qualifier
While MilkMaid's answer is a sound way to go, I would just add a few more behind-the-scenes hints.
Is there a way to do this using CDI (specifically, Weld) if I am not using a Java EE container?
Short answer - there is. Weld can allow for injection of next to any object you wish to have injectable, however you need to mind who owns/manages this object. In your case, it is EntityManager which is stuff from JPA, so guess what - JPA manages the lifecycle of such object. Therefore you need to create a "wrapper" (in reality its a proxy) for such object which will be handled by CDI/Weld. And that what you need producer for.
as if the annotation #PersistenceContext was ignored.
Indeed, it is ignored. Here is a simplification of what happens. Normally, that is in EE container, Weld would make the injection happen but the real magic behind that is not a Weld core code, but rather an integration on the EE server side (who adopts Weld SPI to handle such annotations and turn them into beans which it then injects).
Generally speaking, trying to handle 'EE stuff' outside of EE containers might get tricky as you come across a lot of integration which originally happens inside the container, but you now need to handle that yourself.
Technically one could probably make the #PersistenceContext annotation work, maybe by writing a CDI extension. However, that is a nasty hack rather than anything else - one would be bending the EE-only annotation for SE usage. I would advise against it, but if you still want to go that way, the idea would be to basically make CDI think the #PersistanceContext is yet another #Inject plus provide the producer. This would mean a LOT of manual work, there is no in-built mechanism in CDI to handle that for you - this is normally the EE server's responsibility.
I have a third party jar in my class path which has some services and DAO's developed on top of Spring 2.0.6 and Hibernate3.2.6. I need to call some of the services and daos.
Using ClassPathXmlApplicationContext I'm able to load the application context and able to access the services and daos. Both the service and dao are following ProxyFactoryBean pattern.
Problem comes when I'm accessing a DAO which has some single valued associations.When I'm accessing associated entity I'm getting lazy initialization problem.
To solve this problem:- If it is in my own application JAR I'll be able to change the fetch type into join or in DAOImpl method I could use Hibernate.initialize().
Is there a way to avoid this problem from the stand alone code itself? Or any other way to solve this issue without modifying applicationContext.xml and DAOImpl
You need to put the caller method into one single transaction.
If you have Spring transactional environment, you can put the call of the DAO services/repositories in your own service/method which is marked as #Transactional, or if transaction support is not enabled, but you still have spring support in your application, you can just use TransactionTemplate directly, provided by spring
#Autowire
private PlatformTransactionManager txManager;
TransactionTemplate template = new TransactionTemplate(this.txManager);
template.execute( new TransactionCallback<Object>(){
public void doInTransaction(TransactionStatus status){
// work done here will be wrapped by a transaction and committed.
// status.setRollbackOnly(true) is called or an exception is thrown
}
});
Otherwise you have manually handle transactionality by your own , depending on the technologies your app is using.
I have a question about spring + hibernate
I always use hibernate for my develeppoment, I generate images of the tables and the class DAO
then at logic metier I make simple calls to these methods dao ....
for exemple UserDao=new UserDao () then userdao.persist() ...
Now I have intgret spring, and I do not yet understand ..
1
what is the plus made by him knowing that he is also making calls
has dao Service (the writings that manually) it does not generate the
class dao with hibernate
2
is that with spring I would not worry about manage session for
example open session, close session commit() ...
thank you in advance I would like to have an idea Ccool:
At its core, Spring is a dependency injection framework. This means that instead of doing
public class MyService
private MyDao dao;
public MyService() {
dao = new MyDao();
}
}
You can do
public class MyService
private MyDao dao;
#Autowired
public MyService(MyDao dao) {
this.dao = dao;
}
}
And Spring will automatically call the constructor and inject an instance of MyDao. The main benefit is that the code is easily unit-testable.
On top of that, it allows injecting proxies instead of the actual implementations directly. These proxies will indeed handle the transaction management for you, and more (exception translation, security checks, etc.).
So instead of explicitely opening, committing and rollbacking transactions, you would simply annotate a service method with #Transactional, and Spring would open, commit/rollback the transaction. And the transaction context would automatically propagate to the nested service calls.
This short answer is only to give you an idea. To learn more, read about dependency injection, and read the Spring documentation.
Use Spring annotations like #Service for service classes, #Repository for Dao classes and #Controller for action controllers. Use of #Transactional on service class or methods is suffice to carry out transactions.