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 }
