Java语言。对Java对象集合中的精确值进行分组和求和

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class GroupingAndSumming {
    public static void main(String[] args) {
        // 创建一个示例的Java对象集合
        List<MyObject> objects = new ArrayList<>();
        objects.add(new MyObject("Group1", 10));
        objects.add(new MyObject("Group1", 20));
        objects.add(new MyObject("Group2", 30));
        objects.add(new MyObject("Group2", 40));
        objects.add(new MyObject("Group2", 50));

        // 使用HashMap进行分组和求和
        Map<String, Integer> sumByGroup = new HashMap<>();
        for (MyObject obj : objects) {
            String group = obj.getGroup();
            int value = obj.getValue();

            // 分组
            if (!sumByGroup.containsKey(group)) {
                sumByGroup.put(group, 0);
            }

            // 求和
            sumByGroup.put(group, sumByGroup.get(group) + value);
        }

        // 输出结果
        for (Map.Entry<String, Integer> entry : sumByGroup.entrySet()) {
            System.out.println("Group: " + entry.getKey() + ", Sum: " + entry.getValue());
        }
    }
}

class MyObject {
    private String group;
    private int value;

    public MyObject(String group, int value) {
        this.group = group;
        this.value = value;
    }

    public String getGroup() {
        return group;
    }

    public int getValue() {
        return value;
    }
}