Hibernate - how to generate id manually?

Question

I am working on data migration from one db to a new one in Java. One of my issues are that I must keep the same id values of the entities.

I know it's possible to change the id generator, but I need to set the id manually. Each entity I create using Map from old object to a new one and I just set values. can't I just set manually something like:

Map<String, Object> newEntity = new HashMap<String, Object>()
newEntity.setId(oldEntity.get("id"))

Answer 1

I succeeded in doing it. In my entity I set the following:

@Id
private String id

private Date created
private Date modified

static mapping = {
    id column: 'id', generator: 'assigned'
}

public String getId() {
    return id;
}
public void setId(String id) {
    this.id = id;
}

public Date getCreated() {
    return created;
}

public void setCreated(Date created) {
    this.created = created;
}
public Date getModified() {
    return modified;
}
public void setModified(Date modified) {
    this.modified = modified;
}

and it worked. Thanks!