multithreading - Getting LazyInitializationException "could not initialize proxy - no Session" when running a transaction in a background thread -

multithreading - Getting LazyInitializationException "could not initialize proxy - no Session" when running a transaction in a background thread -

i have unusual problem:

say have 2 entity classes, e.g. container , containedobject. container has @onetomany relationship containedobject.

when getting contained objects directly, works fine, when running background thread, "could not initialize proxy - no session".

example:

@component public class { @autowired private containerrepository _repo; public void doinforeground() { container container = _repo.findone(42l); // suppose 42 exists container.getcontainedobjects().size(); // succeeds } public void submittobackground() { completablefuture<void> f = completablefuture.supplyasync(() -> doinbackground()); } private void doinbackground() { container container = _repo.findone(42l); container.getcontainedobjects().size(); // throws lazyinitializationexception } }

the containerrepository pagingandsortingrepository. running doinforegroundsucceeds, submittobackground throws well-known lazyinitializationexception "could not initialize proxy - no session"

it seems if no transaction started or closed fast. annotating of methods @transactional not help either.

is not possible utilize spring-jpa in background threads or additional magic needed?

1) need readonly transaction lazy collections.

2) suppose @transactional doesn't work on local methods because when phone call local method phone call implementation directly, not proxy object created spring.

if it's case there @ to the lowest degree 2 choices:

1) switch aspectj

<tx:annotation-driven mode="aspectj" proxy-target-class="true"/>

2) create transaction manually using transactiontemplate within doinforeground(): http://simplespringtutorial.com/springprogrammatictransactions.html

multithreading spring hibernate jpa