I am working with enterprise application that uses Spring 3.x with Hibernate annotated programming.I am working with hibernate Session object for performing db operations in my XYZDaoImpl class.
And my doubt is "Is it correct way to close Hibernate Session object every time after performing any CRUD operation?"
If it is not the correct way, please advise me the recommended way of opening/closing of hibernate Session Object.
can you post a bit daoImpl code......
If you use sessionFactory.getCurrentSession(), you will get current session..in this case framework automatically flushed and closed when the transaction ends (commit or rollback).
If you use sessionFactory.openSession(), you have to manage the session yourself and to flush and close it "manually".
No, when using hibernate with spring, you should not (manually) open or close sessions, but let spring manage the hibernate session for you. Spring manages the session as a transactional resource, so you have to configure transaction management correctly.
If you open/close the hibernate session manually, you are hardly using the integration between these two frameworks: the session management is the main feature of the integration.
The only reason to open/close a hibernate session in a spring context is to use the same session to span multiple transactions.
Related
Famous threads like LazyInitializationException with Spring Data JpaRepositories
mention many solutions to LazyInitializationException but do not mention reattaching the detached entity to a (new?) session when you want to lazy load the rest of the associated entities.
Is that because it can't happen ? If it is possible why isn't it mentioned as an alternative?
Most importantly how can you do that with Spring Data Jpa? Do you need to call the underlying Hibernate update() call in order to reattach? And as with Spring to which session do you attach if the session has already been closed after a Service call to the Repository? do you span a new session by calling into the repository again and with which JPA construct/command?
Is there any way to prevent spring data from closing the underlying hibernate session after an #Transactional method in a #Service component? I am writing a simple command line app that reads data from a web service, does some processing and writes to the database. Some of the operations span multiple entities and must be transactional.
However, I am running into too many LazyLoadingExceptions. Apparently the hibernate session is automatically closed by spring after the transaction commits.
In other words, what I am trying to achieve is something like OpenSessionInView, but for a command line app. I could achieve this by using pure JPA and manually handling the entity manager and transactions. However, I would like to know if is there a solution which enables to leverage the spring-data and still achieve the desired behavior.
Two spring boot applications are connected to the common database.
I just wanted to know, how to handle the transaction if both the application try to update the record at the same time?
Since you seem to use JPA (via Spring Data JPA) there isn't much to handle.
The database itself will prevent two transactions to update the record at the same time. So one will always be first.
If you use optimistic locking (which is the default with JPA) the second transaction will notice the modified row and rollback.
Without that the second transaction will simply overwrite the changes with it's own changes.
I have a Spring, Spring Data, JPA/Hibernate application.
The legacy part of the application uses JdbcTemplate the new stuff uses spring-data/hibernate and everything is wrapped in a transaction.
Problem is when I modify an entity via hibernate and the legacy part of the system attempts to query something that's been modified I don't get the updated values with out having to explicitly "flush" the entity manager each time.
Is it possible execute the JdbcTemplate queries against hibernate's first-level cache?
What about trying this?
Edit: https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/orm/jpa/JpaTransactionManager.html
This transaction manager also supports direct DataSource access within a transaction (i.e. plain JDBC code working with the same DataSource). This allows for mixing services which access JPA and services which use plain JDBC (without being aware of JPA)! Application code needs to stick to the same simple Connection lookup pattern as with DataSourceTransactionManager (i.e. DataSourceUtils.getConnection(javax.sql.DataSource) or going through a TransactionAwareDataSourceProxy). Note that this requires a vendor-specific JpaDialect to be configured.
I have a spring application which is based on Spring Batch. By default spring batch introduces transaction for its steps (i.e. at reader,writer and processor) . There are certain stages where I don't really need transaction to be enabled. Because transaction is enabled unnecessary for these methods its giving me some runtime errors as I am making call to two different databases in one method.
Is there any annotation which spring provides to DISABLE transaction for a specific set of methods ?
OR is there anything available in spring batch which can allow me to get rid of transaction either completely or declarative
I am even open to the solution which can disable transaction globally.
Any link , paper will greatly be appreciated.
Thanks in advance
Samir
Spring Batch is inherently transactional. Even if your datasources are not transactional, the semantics of the JobRepository require it. The closest you can get with Spring Batch and not being transactional is using the ResourcelessTransactionManager. This transaction manager is essentially a no-op transaction manager that just keeps track of if an operation is within the scope of a transaction or not.