The Java 8 Stream API could come in handy when you would like to generate a series of objects for example for using them in a unit test.
The following snippet generates a list of 5 User objects with the id and name populated:
List<User> users = IntStream.range(0, 5).mapToObj(i -> {
User user = new User();
user.setId(i);
user.setName(USER_NAME_PREFIX + String.valueOf(i));
return user;
}).collect(Collectors.toList());
If you have a suitable constructor, you can even make it a lot shorter:
List<User> users = IntStream.range(0, 5)
.mapToObj(i -> new User(i, USER_NAME_PREFIX + String.valueOf(i)))
.collect(Collectors.toList());