根据id名称和父id名称构建树结构

根据id名称和父id名称构建树结构

package diit.platform.bussiness.utils;

import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class TreeUtils {

    public static <T> List<T> buildTree(String idName, String parentIdName, List<T> dataList) throws Exception {
        // 创建一个 Map，用来存储 id 到数据对象的映射
        Map<Object, T> dataMap = new HashMap<>();
        for (T data : dataList) {
            Field idField = data.getClass().getDeclaredField(idName);
            idField.setAccessible(true);
            Object idValue = idField.get(data);
            dataMap.put(idValue, data);
        }

        // 创建一个 List，用来存储树的根节点
        List<T> rootList = new ArrayList<>();

        for (T data : dataList) {
            Field parentIdField = data.getClass().getDeclaredField(parentIdName);
            parentIdField.setAccessible(true);
            Object parentIdValue = parentIdField.get(data);

            if (parentIdValue == null || "".equals(parentIdValue.toString())) {
                // 如果 parentId 为 null 或者为空字符串，那么这个节点是根节点
                rootList.add(data);
            } else {
                // 否则，这个节点是某个已存在节点的子节点
                T parentData = dataMap.get(parentIdValue);
                if (parentData != null) {
                    Field childrenField = parentData.getClass().getDeclaredField("children");
                    childrenField.setAccessible(true);
                    List<T> childrenList = (List<T>) childrenField.get(parentData);
                    if (childrenList == null) {
                        childrenList = new ArrayList<>();
                        childrenField.set(parentData, childrenList);
                    }
                    childrenList.add(data);
                }
            }
        }

        return rootList;
    }
}