Hibernate: How to update an Object

It's been a month since I'm dealing with Hibernate and apparently I really like the idea of having an OOP Database. But I have a little problem when trying to update an object (in SQL, you can simply use update syntax).

Hibernate: Illegal attempt to associate a collection with two open sessions

I got this error when I try to update multiple times. My case is a student tries to enroll multiple classes. My data access object (called KelasDAO) only support a student enrolling a single class. So I use a loop to go through the collection and add each class by calling the method. And this error occurred.

Hibernate: Many to Many mapping Error

This is my 3rd month using Hibernate and still I have trouble understanding how it works completely. I'm currently building an information system for my campus, and I use Struts+Hibernate to get it organised.

My recent problem is related to the many-to-many relation between two table. Hibernate allows you to simplify Many-to-Many calls by using a collection object on the class. I have no problem when viewing the list but adding it seems to be more complex.

Movie Review: Transformers: Age of Extinction

Ey ehloo! I'm back! Let's see if my english are geting beter or bader

It's the fourth iteration of the Transformers on the big screen. It's definitely bigger, but does it better? Here is my review on it

Game Review: Kingdom Rush Frontiers HD

For the past 2 months, I've spent my spare time playing Kingdom Rush Frontiers on my iPad. As a huge fans of the first series, this is a breath of fresh air. Here is my review on the second one.