Example usage of the Stream API from JDK8.

Streams.java

List<String> ss = new ArrayList<>();
ss.add("x,y,z");
ss.add("x.y.z");
ss.add("a,b,c");
ss.add("i,j,k");

String result = ss.stream()
    .map(s -> s.replace(",", "."))
    .filter(s -> !s.contains("b"))
    .distinct()
    .sorted()
    .collect(Collectors.toStringJoiner(",")).toString();

System.out.println("Result: " + result);

== Output ==
Result: i.j.k,x.y.z