流计算年末促销

import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.api.common.functions.MapFunction;

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

        DataStream<String> text = env.socketTextStream("localhost", 9999);

        DataStream<Double> numbers = text.map(new MapFunction<String, Double>() {
            @Override
            public Double map(String value) {
                return Double.parseDouble(value);
            }
        });

        DataStream<Double> average = numbers.timeWindowAll(Time.seconds(5)).reduce((a, b) -> (a + b) / 2);

        average.print();

        env.execute("Streaming Average Calculation");
    }
}