public static void main(String[] args) {
        List<Map<String, String>> list = new ArrayList<>();
        Map<String, String> map = new HashMap<>();
        Map<String, String> map1 = new HashMap<>();
        Map<String, String> map2 = new HashMap<>();
        Map<String, String> map3 = new HashMap<>();
        map.put("name", "zhangsan");
        map.put("sortRule", "d");
        map1.put("name", "lisi");
        map1.put("sortRule", "a");
        map2.put("name", "wangwu");
        map2.put("sortRule", "b");
        map3.put("name", "wangwu");
        map3.put("sortRule", "a");
        list.add(map);
        list.add(map1);
        list.add(map2);
        list.add(map3);
        System.out.println("排序前:"+list);
        Collections.sort(list, new Comparator<Map<String, String>>() {
            @Override
            public int compare(Map<String, String> m1, Map<String, String> m2) {
                String m1Key = m1.get("sortRule");
                String m2Key = m2.get("sortRule");
                int i = m1Key.compareTo(m2Key);
                if(i>0){
                    return 1;
                }else if(i<0){
                    return -1;
                }else{
                    return 0;
                }
            }
        }); 
        System.out.println("排序后:"+list);
    }