I'm not sure for JPA 1.0 but you can pass a Collection in JPA 2.0:
String qlString = "select item from Item item where item.name IN :names";
Query q = em.createQuery(qlString, Item.class);
List<String> names = Arrays.asList("foo", "bar");
q.setParameter("names", names);
List<Item> actual = q.getResultList();
assertNotNull(actual);
assertEquals(2, actual.size());
Tested with EclipseLInk. With Hibernate 3.5.1, you'll need to surround the parameter with parenthesis:
String qlString = "select item from Item item where item.name IN (:names)";
But this is a bug, the JPQL query in the previous sample is valid JPQL. See HHH-5126.