android list比较字符串并排序

Collections.sort(dataBeanList, new Comparator<JTeacherLetterOfRedit.DataBean>() {    @Override    public int compare(JTeacherLetterOfRedit.DataBean o1, JTeacherLetterOfRedit.DataBean o2) {        return o2.getCreateDate().compareTo(o1.getCreateDate());    }});