Filter based on condition and collect the object

You should not use flatMap if you want to collect Emp objects in the end because it will change every element to something else and it can be quite hard to map them back.

You should put all your logic in a filter: "keep the Emp object if getLanguage contains "java"".

empList.stream()
    .filter(x->x.getLanguage().contains("java"))
    .collect(Collectors.toList());