Android转换集合数据（ArrayList）为Json格式并上传服务器

　　　　使用Gson上传集合数据到服务器，1.最外层用 ArrayMap<String, Object> 封装；2.通过  mRequestParam.put("cmdLineIds", cmdLineIds);存入集合数据；3.用GSON.toJson转换成标准Json字符串传到服务器上。

 @Override
 public Flowable<String> uploadCollectionData(String businessType, List<CmdLineId> cmdLineIds) {
     // ArrayMap<String, Object> mRequestParam;
     mRequestParam.clear();
     mRequestParam.put("businessType", businessType);
 mRequestParam.put("cmdLineIds", cmdLineIds);
     Log.v("yff", "up: " + JsonUtil.map2Json(mRequestParam));// 即 new Gson().toJson(map);
     return mRequestApi.uploadCollectionData(JsonUtil.map2Json(mRequestParam)).compose(TransformerHelper.MapTransformer);
 }

Log：

{
    "cmdLineIds": [
        {
            "cmdLineId": "20180823002001"
        },
        {
            "cmdLineId": "201808280041"
        }
    ],
    "businessType": "E4"
}