流式计算 如何创建

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 {
        // 创建Flink的执行环境
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // 假设我们有一个数据源，这里用一个简单的集合模拟
        DataStream<Integer> numbers = env.fromElements(1, 2, 3, 4, 5);

        // 计算平均值
        DataStream<Double> average = numbers.map(new MapFunction<Integer, Double>() {
            @Override
            public Double map(Integer value) {
                return (double) value;
            }
        }).reduce((a, b) -> (a + b) / 2);

        // 打印结果
        average.print();

        // 执行程序
        env.execute("Streaming Average Calculation");
    }
}