List<Object> list = new ArrayList<Object>();
        Map<String,Object> map1  = new HashMap<String,Object>();
        map1.put("name", "黑龙江");
        JSONObject put = new JSONObject();
        put.put("city", new String[]{"哈尔滨","大庆"});
        map1.put("cities", put.toString());
        list.add(map1);
        
        Map<String,Object> t = new HashMap<String,Object>();
        t.put("name","中国");
        t.put("province", JSONArray.fromObject(list).toString());
        JSONObject j = new JSONObject();
        j.putAll(t);
        System.out.println(j.toString());

{
        "name":"中国",
        "province":[
        {
           "name":"黑龙江",
            "cities":{
                "city":["哈尔滨","大庆"]
            }
         },
         {
            "name":"广东",
            "cities":{
                "city":["广州","深圳","珠海"]
            }
        },
        {
            "name":"*",
            "cities":{
                "city":["台北","*"]
            }
        },
        {
            "name":"*",
            "cities":{
                "city":["乌鲁木齐"]
            }
        }
    ]
    }

// 此范例的另外一种写法。没有用List来装集合，而是用JSONArray

   Map<String,Object> map1  = new HashMap<String,Object>();
        map1.put("name", "黑龙江");
        JSONObject put = new JSONObject();
        put.put("city", new String[]{"哈尔滨","大庆"});
        map1.put("cities", put.toString());
        
        Map<String,Object> map2  = new HashMap<String,Object>();
        map2.put("name", "广东");
        JSONObject put2 = new JSONObject();
        put2.put("city", new String[]{"广州","深圳","珠海"});
        map2.put("cities", put.toString());
        
        Map<String,Object> t = new HashMap<String,Object>();
        t.put("name","中国");
        JSONArray array = new JSONArray();
        array.add(map1);
        array.add(map2);
        t.put("province", array.toString());
        JSONObject j = new JSONObject();
        j.putAll(t);
        j.element("description", "这是描述");
        System.out.println(j.toString());