实时计算 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 RealTimeAverage {
    public static void main(String[] args) throws Exception {
        // 创建Flink的执行环境
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();

        // 创建数据流，这里假设数据来自某个数据源
        DataStream<String> text = env.socketTextStream("localhost", 9999);

        // 将字符串转换为整数
        DataStream<Integer> numbers = text.map(new MapFunction<String, Integer>() {
            @Override
            public Integer map(String value) {
                return Integer.parseInt(value);
            }
        });

        // 计算平均值
        DataStream<Double> average = numbers.map(new MapFunction<Integer, Double>() {
            private long count = 0;
            private double sum = 0.0;

            @Override
            public Double map(Integer value) {
                count++;
                sum += value;
                return sum / count;
            }
        });

        // 打印结果
        average.print();

        // 执行程序
        env.execute("Real-time Average Calculation");
    }
}