java实现省市区转换成树形结构

Question

有一条sql记录。

INSERT INTO `school_info` ( `schoolCode`,   `name`, `schoolAlias`, `enName`, `address`, `provinceCode`, `cityCode`, `areaCode`, `cityName`) VALUES (10086, '测试学校', NULL, NULL, NULL, 330000, 330100, 330101,  'wz');

需求：提取出相关的省，市，区，学校的信息，并组成树状的数据结构。
类似于:

Answer 1

该回答引用chatgpt:
先把所有查出来，然后组装成树
参考一下

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

class Location {
    int code;
    String name;
    List<Location> children;

    Location(int code, String name) {
        this.code = code;
        this.name = name;
        this.children = new ArrayList<>();
    }
}

public class LocationTree {
    public static void main(String[] args) {
        List<Map<String, Object>> records = new ArrayList<>();

        // 假设从数据库中获取到了相关的省市区数据，存储在records列表中

        // 将记录转换为Location对象
        List<Location> locations = buildLocations(records);

        // 构建树状结构
        List<Location> tree = buildTree(locations);

        // 打印树形结构
        printTree(tree, 0);
    }

    private static List<Location> buildLocations(List<Map<String, Object>> records) {
        List<Location> locations = new ArrayList<>();

        for (Map<String, Object> record : records) {
            int code = (int) record.get("code");
            String name = (String) record.get("name");

            Location location = new Location(code, name);
            locations.add(location);
        }

        return locations;
    }

    private static List<Location> buildTree(List<Location> locations) {
        Map<Integer, Location> locationMap = new HashMap<>();

        // 将每个Location对象存储到map中，以code为键
        for (Location location : locations) {
            locationMap.put(location.code, location);
        }

        // 构建树状结构
        List<Location> tree = new ArrayList<>();
        for (Location location : locations) {
            int parentCode = location.code / 10000 * 10000;
            Location parent = locationMap.get(parentCode);
            if (parent != null) {
                parent.children.add(location);
            } else {
                tree.add(location); // 如果没有父节点，将其视为根节点
            }
        }

        return tree;
    }

    private static void printTree(List<Location> tree, int level) {
        for (Location location : tree) {
            for (int i = 0; i < level; i++) {
                System.out.print("  "); // 根据层级缩进
            }
            System.out.println(location.name);

            printTree(location.children, level + 1); // 递归打印子节点
        }
    }
}