01

        //3. 将读取出来的json字符串转换为ItcastDataObj
        SingleOutputStreamOperator<ItcastDataObj> vehicleDataStream = source.map(
                new MapFunction<String, ItcastDataObj>() {
                    @Override
                    public ItcastDataObj map(String line) throws Exception {
                        return JsonParseUtil.parseJsonToObject(line);
                    }
                }
        );
        //-- 另种写法
        DataStream<ItcastDataObj> vehicleDataStream02 = source.map(JsonParseUtil::parseJsonToObject);