Custom

package com.atguigu.watermark;

import com.atguigu.bean.WaterSensor;
import com.atguigu.functions.WaterSensorMapFunction;
import org.apache.commons.lang3.time.DateFormatUtils;
import org.apache.flink.api.common.eventtime.WatermarkStrategy;
import org.apache.flink.streaming.api.datastream.SingleOutputStreamOperator;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.windowing.ProcessWindowFunction;
import org.apache.flink.streaming.api.windowing.assigners.TumblingEventTimeWindows;
import org.apache.flink.streaming.api.windowing.time.Time;
import org.apache.flink.streaming.api.windowing.windows.TimeWindow;
import org.apache.flink.util.Collector;

public class WatermarkCustomDemo {
    public static void main(String[] args) throws Exception {
        StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        env.setParallelism(1);

        // 默认周期 200ms
        env.getConfig().setAutoWatermarkInterval(2000);

        SingleOutputStreamOperator<WaterSensor> sensorDS = env
                .socketTextStream("192.168.1.7", 9091)
                .map(new WaterSensorMapFunction());

        WatermarkStrategy<WaterSensor> watermarkStrategy = WatermarkStrategy
                // TODO 指定 自定义的 生成器
                // 1.自定义的 周期性生成
//                .<WaterSensor>forGenerator(ctx -> new MyPeriodWatermarkGenerator<>(3000L))
                // 2.自定义的 断点式生成
                .<WaterSensor>forGenerator(ctx -> new MyPuntuatedWatermarkGenerator<>(3000L))
                .withTimestampAssigner(
                        (element, recordTimestamp) -> {
                            return element.getTs() * 1000L;
                        });

        SingleOutputStreamOperator<WaterSensor> sensorDSwithWatermark = sensorDS.assignTimestampsAndWatermarks(watermarkStrategy);

        sensorDSwithWatermark.keyBy(sensor -> sensor.getId())
                .window(TumblingEventTimeWindows.of(Time.seconds(10)))
                .process(
                        new ProcessWindowFunction<WaterSensor, String, String, TimeWindow>() {
                            @Override
                            public void process(String s, Context context, Iterable<WaterSensor> elements, Collector<String> out) throws Exception {
                                long startTs = context.window().getStart();
                                long endTs = context.window().getEnd();
                                String windowStart = DateFormatUtils.format(startTs, "yyyy-MM-dd HH:mm:ss.SSS");
                                String windowEnd = DateFormatUtils.format(endTs, "yyyy-MM-dd HH:mm:ss.SSS");

                                long count = elements.spliterator().estimateSize();

                                out.collect("key=" + s + "的窗口[" + windowStart + "," + windowEnd + ")包含" + count + "条数据===>" + elements.toString());
                            }
                        }
                )
                .print();

        env.execute();
    }
}

package com.atguigu.watermark;

import org.apache.flink.api.common.eventtime.Watermark;
import org.apache.flink.api.common.eventtime.WatermarkGenerator;
import org.apache.flink.api.common.eventtime.WatermarkOutput;

public class MyPuntuatedWatermarkGenerator<T> implements WatermarkGenerator<T> {
    // 乱序等待时间
    private long delayTs;
    // 用来保存 当前为止 最大的事件时间
    private long maxTs;

    public MyPuntuatedWatermarkGenerator(long delayTs) {
        this.delayTs = delayTs;
        this.maxTs = Long.MIN_VALUE + this.delayTs + 1;
    }

    /**
     * 每条数据来，都会调用一次： 用来提取最大的事件时间，保存下来,并发射watermark
     *
     * @param event
     * @param eventTimestamp 提取到的数据的 事件时间
     * @param output
     */
    @Override
    public void onEvent(T event, long eventTimestamp, WatermarkOutput output) {
        maxTs = Math.max(maxTs, eventTimestamp);
        output.emitWatermark(new Watermark(maxTs - delayTs - 1));
        System.out.println("调用onEvent方法，获取目前为止的最大时间戳=" + maxTs+",watermark="+(maxTs - delayTs - 1));
    }

    /**
     * 周期性调用： 不需要
     *
     * @param output
     */
    @Override
    public void onPeriodicEmit(WatermarkOutput output) {

    }
}