I'm new to Java EE and I have a problem to add relation to an entity.
I've the following entities:
All works fine except when I try to relate a printer to an user. The first time the relation is written in the db. If I try to add another printer to the same user, I loose the first relation. I'm not able to add more than one printer to the same user. I tried a lot of solutions without result, the following is the last attempt to solve the problem.
Part of UsersEJB.java
Part of PrintersEJB.java
How can I solve the problem? Someone know book/sites where I can find real examples to use all the relations?
posted 4 years ago
A few things,
Users and Printers make no sense as class names, they should be singular, User, Printer.
In your User the printer @OneToMany should use a mappedBy="owner" not a @JoinColumn.
Nowhere in your savePrinter code do you add the printer to the user, you need to do this.