@CompileStatic
class GormSharedSessionMongoTransactionManager
extends DatastoreTransactionManager

A PlatformTransactionManager that drives a single GORM MongoDB transaction and additionally exposes its com.mongodb.client.ClientSession to Spring Data MongoDB, so that GORM operations and MongoTemplate/repository operations executed within one @Transactional method participate in the same MongoDB transaction.

It extends DatastoreTransactionManager — inheriting GORM's begin/commit/rollback, session binding and flushing — and, once GORM has started its com.mongodb.client.ClientSession, binds a Spring Data MongoResourceHolder referencing that same session, keyed by the MongoDatabaseFactory. Spring Data's MongoTemplate discovers that holder via the thread-bound resources and runs inside the session, so a single commit (or abort) — driven by GORM — applies to both stacks atomically.

This requires GORM server-side transactions to be enabled (grails.mongodb.transactional = true); without an active com.mongodb.client.ClientSession there is nothing to share and Spring Data operations run outside of a transaction as before.

Propagation: as for GORM's DatastoreTransactionManager. A transaction started inside another joins it, for Spring Data as for GORM. REQUIRES_NEW suspends both: the new transaction runs in a GORM session and com.mongodb.client.ClientSession of its own, which its MongoTemplate calls use, and the outer transaction's are restored when it completes. A transaction begun in a session of its own (withNewSession) likewise runs its MongoTemplate calls in its own com.mongodb.client.ClientSession, or, read-only, without one, and the surrounding transaction's is put back when it completes. NESTED is not supported.

Since:

8.0