如何基于 Flink 生成在线机器学习的样本？

public class StateSampleFunction extends KeyedProcessFunction<String, Tuple2, ReturnSample> {    /**     * 这个状态是通过过程函数来维护,使用ValueState     */    private ValueState state;
    private Long timer = null;
    public StateSampleFunction (String time){        timer = Long.valueOf(time);    }
    @Override    public void open(Configuration parameters) throws Exception {        // 获取state        state = getRuntimeContext().getState(new ValueStateDescriptor<>("state", TypeInformation.of(new TypeHint< ReturnSample >() {})));    }
    @Override    public void processElement(Tuple2value, Context context, Collector< ReturnSample > collector) throws Exception {        if (value.f0 == null){            return;        }
        Object sampleValue = value.f1;        Long time = context.timerService().currentProcessingTime();        ReturnSample returnSample = state.value();        if (returnSample == null) {            returnSample = new ReturnSample();            returnSample.setKey(value.f0);            returnSample.setTime(time);            context.timerService().registerProcessingTimeTimer(time +timer);        }
        // 更新点击数据到state里        if (sampleValue instanceof ClickLog){            ClickLog clickLog = (ClickLog)values;            returnSample =(ReturnSample) clickLog.setSample(returnSample);        }        state.update(returnSample);    }
    /**     * @param timestamp     * @param ctx     * @param out     * @throws Exception     */    @Override    public void onTimer(long timestamp, OnTimerContext ctx, Collector< ReturnSample > out) throws Exception {        ReturnSample value = state.value();        state.clear();        out.collect(value);    }}