使用Java Stream实例化具有索引和特定枚举值的不同数量的新对象

import java.util.*;
import java.util.stream.*;

enum Status {
    ACTIVE, INACTIVE, PENDING
}

class MyObject {
    private String name;
    private Status status;

    public MyObject(String name, Status status) {
        this.name = name;
        this.status = status;
    }

    @Override
    public String toString() {
        return "MyObject{" +
                "name='" + name + '\'' +
                ", status=" + status +
                '}';
    }
}

public class StreamExample {
    public static void main(String[] args) {
        List<MyObject> objects = Arrays.asList(
                new MyObject("Obj1", Status.ACTIVE),
                new MyObject("Obj2", Status.INACTIVE),
                new MyObject("Obj3", Status.PENDING),
                new MyObject("Obj4", Status.ACTIVE)
        );

        Map<Status, Long> countByStatus = objects.stream()
                .collect(Collectors.groupingBy(MyObject::getStatus, Collectors.counting()));

        System.out.println("Count by status: " + countByStatus);

        Map<Status, List<MyObject>> filteredByStatus = objects.stream()
                .filter(obj -> obj.getStatus() == Status.ACTIVE)
                .collect(Collectors.groupingBy(MyObject::getStatus));

        System.out.println("Filtered by status: " + filteredByStatus);
    }
}

Map<Status, Integer> countMap = new EnumMap<>(Status.class);
countMap.put(Status.ACTIVE, 3);
countMap.put(Status.INACTIVE, 2);
countMap.put(Status.PENDING, 1);

List<MyObject> newObjects = countMap.entrySet().stream()
        .flatMap(entry -> IntStream.range(0, entry.getValue())
                .mapToObj(i -> new MyObject("Obj" + (i + 1), entry.getKey())))
        .collect(Collectors.toList());

System.out.println("New objects: " + newObjects);