JPA OneToOne and ManyToMany between two entities

Question

I asked a question earlier, but think it wasn\'t clear enough i will elaborate further with the code.
I have a Teacher entity and Department entity
Many Teachers

Answer 1

This is not a JPA problem, but is caused by recursive instantiation of Teacher/Department.

When you create, or ask JPA to create, an instance of Teacher, the Teacher attempts to instantiate a Department, which instantiates a Teacher ..., to infinity.

Hence you're seeing a StackOverflowError error near the end of that stack trace.

Remove the = new Teacher() and = new Department() expressions from the class definition; depend on and use appropriate setter methods when you create them.