java8 List中指定某个对象去重，lambda表达式解决

判断是否有重复数据，有重复不加到map中

 private static <T> Predicate<T> distinctByKey(Function<? super T, ?> keyExtractor) {
        Map<Object, Boolean> seen = new ConcurrentHashMap<>();
        return t -> seen.putIfAbsent(keyExtractor.apply(t), Boolean.TRUE) == null;
    }

将数据存入List,再用list调用java的stream() api 的过滤方法filter(),将上面的方法传入，方法中传实体的字段，可实现根据字段过滤重复数据

List<entry>list=new List<>
 List<?> distinct = list.stream().filter(distinctByKey(entry::get***)).collect(Collectors.toList());