Half done. Would finish it this weekend(or if really unluckily, before next weekend ends) Wanna ask, if you mind me stay the legacy apis, or wanna migrate to a suit of new apis.
import org.apache.flink.streaming.api.functions.sink.legacy.PrintSinkFunction; import org.apache.flink.streaming.api.functions.sink.legacy.SinkFunction; import org.apache.flink.streaming.api.functions.source.legacy.SourceFunction; if you mean it.
