java8 去重属性增强

通过Stream.filter不同属性来过滤重复

    /**
     * 通过对象属性去重
     *
     * @param keyExtractor
     * @param <T>
     * @return
     */
    public static <T> Predicate<T> distinctByKey(Function<? super T, Object> keyExtractor) {
        Set<Object> seen = ConcurrentHashMap.newKeySet();
        return t -> seen.add(keyExtractor.apply(t));
    }

根据属性去重，并且进行信息整合

    /**
     * 通过对象属性去重，并对相同Key的对象执行操作，适合两个list相同属性并集
     *
     * @param keyExtractor
     * @param thenFunction
     * @param <T>
     * @return
     */
    public static <T> Predicate<T> distinctAndThen(Function<? super T, Object> keyExtractor,
                                                   BiConsumer<T, T> thenFunction) {
        Map<Object, T> map = new ConcurrentHashMap<>(10);
        return t -> {
            if (map.containsKey(keyExtractor.apply(t))) {
                thenFunction.accept(t, map.get(keyExtractor.apply(t)));
                return false;
            } else {
                map.put(keyExtractor.apply(t), t);
                return true;
            }
        };
    }