Java 8流-聚合和返回聚合步骤

import java.util.Arrays;
import java.util.List;

public class StreamExample {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

        // 聚合操作：求和
        int sum = numbers.stream()
                .reduce(0, (a, b) -> a + b);
        System.out.println("Sum: " + sum);

        // 聚合操作：求平均值
        double average = numbers.stream()
                .mapToDouble(Integer::doubleValue)
                .average()
                .orElse(0);
        System.out.println("Average: " + average);

        // 聚合操作：最大值
        int max = numbers.stream()
                .max(Integer::compareTo)
                .orElse(0);
        System.out.println("Max: " + max);

        // 聚合操作：最小值
        int min = numbers.stream()
                .min(Integer::compareTo)
                .orElse(0);
        System.out.println("Min: " + min);

        // 聚合操作：计数
        long count = numbers.stream()
                .count();
        System.out.println("Count: " + count);
    }
}