JDK1.8stream根据对象的某一字段去重

List list = new ArrayList<>();
List listByName = list.stream().filter(distinctByName（item -> item.getName()）).collect(Collectors.toList());
private static <T> Predicate<T> distinctByName(Function<? super T , Object> keyExtractor) {      
    Map<Object , Boolean> seen = new ConcurrentHaskMap<>();
    return t -> seen.putIfAbsent(keyExtractor.apply(t)) , Boolean.True) == null;     
    
}