They're very small and the process is more time consuming to do properly. However, Java sparrows are hand raised regularly in huge numbers for the pet trade in Japan. I have two tame Javas which were socialized as young adults. They step up, are not fearful of people at all, and are easily handleable but because they were not imprinted they are not really affectionate with me. I also have society finches which will come fly to me for food, though they become wilder again without daily effort, and I have lapsed in working with them.