在Java8中如何从流中获取Map<String，List<Object>>

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Main {
    public static void main(String[] args) {
        // 创建一个包含多个对象的流
        Stream<MyObject> stream = createStream();

        // 使用流的collect方法和Collectors.groupingBy进行分组
        Map<String, List<Object>> resultMap = stream.collect(Collectors.groupingBy(MyObject::getKey, Collectors.mapping(MyObject::getValue, Collectors.toList())));

        // 输出结果
        resultMap.forEach((key, value) -> System.out.println(key + ": " + value));
    }

    private static Stream<MyObject> createStream() {
        // 创建一个包含多个对象的流
        List<MyObject> objects = List.of(
                new MyObject("key1", "value1"),
                new MyObject("key2", "value2"),
                new MyObject("key1", "value3"),
                new MyObject("key2", "value4")
        );

        return objects.stream();
    }
}

class MyObject {
    private String key;
    private Object value;

    public MyObject(String key, Object value) {
        this.key = key;
        this.value = value;
    }

    public String getKey() {
        return key;
    }

    public Object getValue() {
        return value;
    }
}