java8 lamda expression according to weight a list, according to a list of elements

/ ** 
   * specified according to the field list to re 
   * @param list 
   * @return 
   * / 
  public static List <the DataModel> niqueList (List <the DataModel> list) { 
    // deduplication, the code field according to 
    List <DataModel> uniqueList = list .stream () the collect (. 
            collectingAndThen ( 
                    toCollection (() -> new new TreeSet <> (Comparing (N-> n.getCode ()))), the ArrayList :: new new) 
    ); 
    return uniqueList; 
}

　list java8 element according to the specified weight