List<String> elements = new ArrayList<>();
// The list of strings will be sorted lexicographically
elements.sort();
// You can also implement a custom comparator
Comparator<String> comp = new Comparator<String>(){
@Override
public int compare(final String s1,String s2) {
//TODO return 1 if rhs should be before lhs
// return -1 if lhs should be before rhs
// return 0 otherwise (meaning the order stays the same)
}
};
elements.sort(comp);