Caused by: org.hibernate.HibernateException: identifier of an instance of <class> altered from <x> to <y>

This is caused, spare from you actually doing the ID change, from using f.ex. 'int' instead of 'Integer' as object id.

So, if your code looks like this:

public class HibernateObject {
private int id;

public int getId() {
return this.id;
}

public void setId(int id) {
this.id = id;
}
}

You will have to change it to:

public class HibernateObject {
private Integer id;

public Integer getId() {
return this.id;
}

public void setId(Integer id) {
this.id = id;
}
}

And it works. In my humble opinion this is very silly behaviour, but I guess there is a reason why it works like this.

Hope this helps someone.

I'm using a String type to identify the ID. How can I do?