基于Hutool TreeUtil 实现后端返回数据树形结构

接下来模仿现实业务场景中，实现查询数据库得到数据，最后使用TreeUtil 处理数据，返回结果呈树形结构。

1：引入 Hutool 依赖

<dependency>
    <groupId>cn.hutool</groupId>
    <artifactId>hutool-all</artifactId>
    <version>5.8.11</version>
</dependency>

2：数据库建表语句

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for department
-- ----------------------------
DROP TABLE IF EXISTS `department`;
CREATE TABLE `department`  (
  `id` int NOT NULL COMMENT '主键id 信息',
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL COMMENT '部门名称信息',
  `pid` int NOT NULL COMMENT '父节点id 信息',
  `status` int NULL DEFAULT NULL COMMENT '0：我呼死你 1：你被我打死了',
  `desc` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '对部门信息的描述',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of department
-- ----------------------------
INSERT INTO `department` VALUES (1, '北京阿里云有限公司', 0, 0, '我是大公司');
INSERT INTO `department` VALUES (2, '郑州云智能有限公司', 0, 1, '我是郑州公司');
INSERT INTO `department` VALUES (3, '开发部', 1, 1, '我是大公司下的部门');
INSERT INTO `department` VALUES (4, '测试部', 1, 1, '我是大公司下的部门');
INSERT INTO `department` VALUES (5, '云计算', 2, 1, '我是郑州公司下的部门');
INSERT INTO `department` VALUES (6, '大数据', 2, 1, '我是郑州公司下的部门');
INSERT INTO `department` VALUES (7, '夏天', 3, 1, '我是开发部的成员');
INSERT INTO `department` VALUES (8, '齐天大圣', 3, 1, '我是测试部的成员');
INSERT INTO `department` VALUES (9, '高俊俊', 5, 1, '我是云计算下面的专业');
INSERT INTO `department` VALUES (10, '张三三', 6, 1, '我是大数据的人');

SET FOREIGN_KEY_CHECKS = 1;

3：Result  结果类 以及 ResultCode

public class Result implements Serializable {

    /**
     *
     */
    private static final long serialVersionUID = 1L;

    //状态码
    private Integer code;

    //响应消息
    private String msg;

    //响应数据
    private Object data;
    private Integer count;

    public Integer getCount() {
        return count;
    }

    public void setCount(Integer count) {
        this.count = count;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getData() {
        return data;
    }

    public void setData(Object data) {
        this.data = data;
    }

    public Result(ResultCode resultCode,Object data) {
        this.code=resultCode.getCode();
        this.msg=resultCode.getMsg();
        this.data=data;
    }
    public Result(Integer code,String msg,Object data) {
        this.code=code;
        this.msg=msg;
        this.data=data;
    }

}



//ResultCode  类
public enum ResultCode {
  SUCCESS(0,"成功"),
  ERROR(500,"操作失败"),
  private Integer code;

    private String msg;

    public Integer getCode() {
        return code;
    }
    public void setCode(Integer code) {
        this.code = code;
    }
    public String getMsg() {
        return msg;
    }
    public void setMsg(String msg) {
        this.msg = msg;
    }
    ResultCode(Integer code,String msg){
        this.code=code;
        this.msg=msg;
    }

}

4：实体类

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Department {
        private Integer id;
        private String name;
        private Integer pid;   //父id
        private Integer status; 
        private String desc;
        /**
         * 子目录列表
         */
        private List<Department> treeNode;
}

5：Controller 层

@RestController
@RequestMapping("/department")
public class DepartmentController {
    @Resource
    private DepartmentService departmentService;
    @PostMapping("treeDepartment")
    public Result treeDepartment(){
        List<Tree<String>> departmentAll = departmentService.findDepartmentAll();
        return new Result(ResultCode.SUCCESS,departmentAll);
    }
}

6：service 层

接口：

@Service
public interface DepartmentService {
    List<Tree<String>> findDepartmentAll();
}

实现类：

@Service
public class DepartmentSericeImpl implements DepartmentService {
    @Resource
    private DepartmentMapper departmentMapper;
    private static final String status = "status";
    private static final String desc = "desc";
    @Override
    public List<Tree<String>> findDepartmentAll() {
        List<Department> list = departmentMapper.findDepartmentAll();
        List<Department> list2 = CollUtil.newArrayList();
        //浅拷贝赋值
        list2.addAll(list);
        // rootId
        String pid = "0";
        //配置
        TreeNodeConfig nodeConfig = new TreeNodeConfig();
        // 自定义属性名 都要默认值的
        //设置ID对应的名称
        nodeConfig.setIdKey("id");
        // 最大递归深度 3级目录
        nodeConfig.setDeep(3);
//        入参
//        tree:  最终要返回的数据
//        node:  lists数据

//        返回
//        Tree<String>
//        Tree: 转换的实体 为数据源里的对象类型
//        String: ID类型
        //转换器
        List<Tree<String>> treeList = TreeUtil.build(list2, pid, nodeConfig,
                (node, tree) -> {
            //id
            tree.setId(node.getId().toString());
            //姓名
            tree.setName(node.getName());
            //获取父节点id
            tree.setParentId(node.getPid().toString());
            // 扩展的属性 ...
            tree.putExtra(status, node.getStatus());
            tree.putExtra(desc, node.getDesc());

        });
        return treeList;
    }
}

 

7：mapper 层

@Mapper
public interface DepartmentMapper {
    List<Department> findDepartmentAll();
}

mapper.xml文件：

<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.example.demotest.mapper.DepartmentMapper">
    <select id="findDepartmentAll" resultType="com.example.demotest.pojo.Department">
        select * from department
    </select>
</mapper>

8：查询结果如下

{
    "code": 0,
    "msg": "成功",
    "data": [
        {
            "id": "1",
            "name": "北京阿里云有限公司",
            "parentId": "0",
            "status": 0,
            "desc": "我是大公司",
            "children": [
                {
                    "id": "3",
                    "name": "开发部",
                    "parentId": "1",
                    "status": 1,
                    "desc": "我是大公司下的部门",
                    "children": [
                        {
                            "id": "7",
                            "name": "夏天",
                            "parentId": "3",
                            "status": 1,
                            "desc": "我是开发部的成员",
                            "children": null
                        },
                        {
                            "id": "8",
                            "name": "齐天大圣",
                            "parentId": "3",
                            "status": 1,
                            "desc": "我是测试部的成员",
                            "children": null
                        }
                    ]
                },
                {
                    "id": "4",
                    "name": "测试部",
                    "parentId": "1",
                    "status": 1,
                    "desc": "我是大公司下的部门"
                }
            ]
        },
        {
            "id": "2",
            "name": "郑州云智能有限公司",
            "parentId": "0",
            "status": 1,
            "desc": "我是郑州公司",
            "children": [
                {
                    "id": "5",
                    "name": "云计算",
                    "parentId": "2",
                    "status": 1,
                    "desc": "我是郑州公司下的部门",
                    "children": [
                        {
                            "id": "9",
                            "name": "高俊俊",
                            "parentId": "5",
                            "status": 1,
                            "desc": "我是云计算下面的专业",
                            "children": null
                        }
                    ]
                },
                {
                    "id": "6",
                    "name": "大数据",
                    "parentId": "2",
                    "status": 1,
                    "desc": "我是郑州公司下的部门",
                    "children": [
                        {
                            "id": "10",
                            "name": "张三三",
                            "parentId": "6",
                            "status": 1,
                            "desc": "我是大数据的人",
                            "children": null
                        }
                    ]
                }
            ]
        }
    ],
    "count": null
}