Jpa Exception: Failed to Lazily Initialize a Collection of Role Could Not Initialize Proxy – no Session

异常描述

Jpa Exception: Failed to Lazily Initialize a Collection of Role Could Not Initialize Proxy – no Session

When and why dose the exception happen

when two entities are in association mapping with fetch = FetchType.LAZY (for eg. OneToMany relationship) and we try to get child entity from the parent entity after session gets closed.

解决方案

How to fix the exception

• Fixing by using @Transactional annotation.
• Fixing by calling child entity in a separate method before the session is closed.
• Fixing by defining enable_lazy_load_no_trans = true in application.properties file.
• Fixing by fetch = FetchType.EAGER.( I think this is not a good solution. )

Failed to lazily initialize a collection of role could not initialize proxy – no Session