SubclassI sci = new SubclassI();
sci.setId(1);
sci.setClassIName("SubclassIName");
sci.setName("SubclassIBaseClassName");
SubclassJ scj = new SubclassJ();
scj.setId(2);
scj.setClassJName("SubclassJName");
scj.setName("SubclassJBaseClassName");
em.getTransaction().begin();
em.persist(sci);
em.persist(scj);
em.getTransaction().commit();