设窗口为5，延迟为3。
假如数据为：0 1 2 5 6 7 3 4 8
则两个窗口为 ：
window = TimeWindow{start=0, end=5}
0
1
2
3
4
window = TimeWindow{start=5, end=10}
5
6
7
8
即：5 6 7 的数据不会包含在 TimeWindow{start=0, end=5} 里。
验证程序：
public class FlinkWindowExample {
public static void main(String[] args) throws Exception {
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
env.setParallelism(1);
DataStreamSource<String> ds = env.socketTextStream("worker1", 7777);
SingleOutputStreamOperator<Integer> watermarks = ds
.map(Integer::parseInt)
.assignTimestampsAndWatermarks(WatermarkStrategy
.<Integer>forBoundedOutOfOrderness(Duration.ofMillis(3))
.withTimestampAssigner((event, timestamp) -> event));
SingleOutputStreamOperator<Integer> windowedStream = watermarks
.windowAll(TumblingEventTimeWindows.of(Time.milliseconds(5)))
.apply(new AllWindowFunction<Integer, Integer, TimeWindow>() {
@Override
public void apply(TimeWindow window, Iterable<Integer> values, Collector<Integer> out) throws Exception {
System.out.println("window = " + window);
for (Integer value : values) {
out.collect(value);
}
}
});
windowedStream.print();
env.execute("Flink Window Example");
}
}
