Scala:
.map(x=> JSON.parseObject(x)) .assignTimestampsAndWatermarks( WatermarkStrategy.forBoundedOutOfOrderness[JSONObject](Duration.ofSeconds(3)) .withTimestampAssigner(new SerializableTimestampAssigner[JSONObject] { override def extractTimestamp(element: JSONObject, recordTimestamp: Long): Long = element.getLong("ts") }) )