The life cycle and scope

Lifecycle and scope

Lifetime, and scope are critical, because incorrect usage can lead to very serious concurrency problems!

SqlSessionFactoryBuilder:

• Once the SqlSessionFactory is created, it is no longer needed
• Local variables

SqlSessionFactory:

• Can be imagined as: data connection pool
• Once created, the SqlSessionFactory should exist for the duration of the application's runtime,there is no reason to drop it or recreate another instance.
• So the best scope for SqlSessionFactory is application scope.
• The easiest way is to use Singleton mode or static mode.

SqlSession:

• A request to connect to the connection pool!
• Instances of SqlSession are not thread-safe and therefore cannot be shared, so their optimal scope is request or method scope.
• You need to close it after use, otherwise resources will be occupied!