When we want to clone an object there are several ways to do this For instance we can implement Clonable, which makes it possible to duplicate an object. We also can create a new object manually by calling each setter or use a parameterised constructor. In case we want to clone a Hibernate object, there is an extra option available which is more elegant: the Hibernate3BeanReplicator. The Hibernate3BeanReplicator is provided by Beanlib (http://beanlib.sourceforge.net/) and it supports deep clones, so we can also clone related one-to-one objects easily. For example we want to clone the Student object, including all child (one-to-one) objects.

Student student = studentDao.getStudentById(1);

HibernateBeanReplicator replicator = new Hibernate3BeanReplicator();
Student studentCopy = replicator.deepCopy(student);

studentCopy.setId(null);
studentCopy.getRelatedObject().setId(null);

studentDao.save(studentCopy);

When we use auto increment id's or unique required fields, we manually have to set these values to null or use an unique value. Please note that we also set the Id of the RelatedObject to null. As can be seen cloning an object can be very simple! More information can be found on http://beanlib.svn.sourceforge.net/viewvc/beanlib/trunk/beanlib-doc/hibernate-bean-replicator.html