String jsonStr = "[{"key": 1568607847117,"imgType": "S","count": 1,"level": 2},
 {"key": 1568607914096,"imgType": "C","count": 0,"level": 4}]";

如何拿到 level 的值呢?

JSONObject.parseArray(x).getJSONObject(0).getString("level")

0代表第一个json, 每个json里面的值都需要判断则如下编写:

                JSONArray objects = JSONObject.parseArray(listingPictureSettingDto.getImgTypes());
                for (int i = 0; i<objects.size(); i++) {
                    if (objects.getJSONObject(i).getInteger("count") <= 0) {
                        throw new ValidatorParameterException("请填写完整图片类型项(需大于零)");
                    }
                    if (StringUtil.isEmpty(objects.getJSONObject(i).getInteger("level"))) {
                        throw new ValidatorParameterException("请填写完整优先级项");
                    }
                }