Collections.sort(List<Object>, new Comparator<Object>() {

    public int compare(Object o1, Object o2) {

        return o1.getSort().compareTo(o2.getSort());

    }

});

Collections.sort(articles, new Comparator<Article>() {

    public int compare(Article kf1, Article kf2) {

    　　return kf1.getSort().compareTo(kf2.getSort());

    }

});