SSH frame error: org.hibernate.LazyInitializationException:failed to lazily initialize a collection of role.

There are problems when doing the SSH project exercise:

Org.hibernate.LazyInitializationException:failed to lazily initialize a collection of role

The reason for this is the lazy loading of hibernate problems.
In the multi-party configuration does not specify the mode of loading, and the side of the party is lazy loading, so in the acquisition of one side is acquired, but the time to obtain a multi-party session has been closed, it will not get more information, so error.
Workaround:

The loading mode of multiple parties (One-to-many) in one party is changed to load immediately, and one party in the multiparty (many-to-one) changes to lazy loading.

That is, add lazy= "false" (One-to-many) in a one-to-many party

SSH Framework error: org.hibernate.LazyInitializationException:failed to lazily initialize a collection of role.