Execution Context & Resolver

public interface MongoTemplateResolver<K> {
  MongoExecutionContext getTemplate(K key);
}

ReactiveMongoDsl<K>는 key마다 MongoExecutionContext를 가져옵니다. MongoExecutionContext가 MongoDatabase, ClientSession, collection naming, entity ↔ Document mapping과 save lifecycle hook의 경계를 담당합니다.

MongoClient frontClient = MongoClients.create(frontConnectionString);
MongoClient backClient = MongoClients.create(backConnectionString);

MongoExecutionContext frontContext = new DriverMongoExecutionContext(
    frontClient,
    frontClient.getDatabase("front")
);

MongoExecutionContext backContext = new DriverMongoExecutionContext(
    backClient,
    backClient.getDatabase("back")
);

MongoTemplateResolver<MongoTemplateName> resolver = key ->
    key == MongoTemplateName.BACK ? backContext : frontContext;

기본 collection 이름은 entity simple class name을 decapitalize해서 결정합니다. 프로젝트의 실제 naming 규칙이 다르면 생성자에 collection-name resolver를 전달합니다.

MongoExecutionContext context = new DriverMongoExecutionContext(
    mongoClient,
    mongoDatabase,
    entityClass -> collectionNameResolver(entityClass)
);

If the collection name is completely fixed during the application lifetime, you can use DriverMongoExecutionContext.cachedCollectionNameResolver(...). Do not use cache helper for resolvers that change names based on tenant/request/time.

The ClientSession created in getTxJob(...) is propagated only to the same DSL execution by MongoExecutionContext#getSessionScope(). DriverMongoExecutionContext uses its own MongoClient as the session scope by default.