树形结构

行吧行吧，又做回JAVA了

在springboot中，撰写接口，返回树形图无限分级

一、为了最快做出来，直接三级固定死，在MySql中写死

1.1 在entity中建立子类存放

package *.dataresource.entity.dataobject;

@Data
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
public class MasterBusiness extends BaseDO implements Serializable {//实现树状结构
    private List children;
}

1.2在dal中建立数据库接口

package *.dataresource.dal;

@Repository
public interface IMasterBusinessRepository {//树状查询
    List selectTree();
}

1.3在mapping中配置映射

    <resultMap id="TreeResultMap" type="*.dataresource.entity.dataobject.MasterBusiness">
        <id column="businessId1" property="businessId" jdbcType="INTEGER"/>
        <result column="businessCode1" property="businessCode" jdbcType="VARCHAR"/>
        <result column="businessName1" property="businessName" jdbcType="VARCHAR"/>
        <result column="businessLevel1" property="businessLevel" jdbcType="VARCHAR"/>
        <result column="parentId1" property="parentId" jdbcType="VARCHAR"/>
        <result column="sort1" property="sort" jdbcType="VARCHAR"/>
        <result column="explain1" property="explain" jdbcType="VARCHAR"/>
        <result column="status1" property="status" jdbcType="INTEGER"/>
        <result column="createUser1" property="createUser" jdbcType="VARCHAR"/>
        <result column="createTime1" property="createTime" jdbcType="TIMESTAMP"/>
        <result column="modifyUser1" property="modifyUser" jdbcType="VARCHAR"/>
        <result column="modifyTime1" property="modifyTime" jdbcType="TIMESTAMP"/>
        <collection property="children" ofType="*.dataresource.entity.dataobject.MasterBusiness">
            <id column="businessId2" property="businessId" jdbcType="INTEGER"/>
            <result column="businessCode2" property="businessCode" jdbcType="VARCHAR"/>
            <result column="businessName2" property="businessName" jdbcType="VARCHAR"/>
            <result column="businessLevel2" property="businessLevel" jdbcType="VARCHAR"/>
            <result column="parentId2" property="parentId" jdbcType="VARCHAR"/>
            <result column="sort2" property="sort" jdbcType="VARCHAR"/>
            <result column="explain2" property="explain" jdbcType="VARCHAR"/>
            <result column="status2" property="status" jdbcType="INTEGER"/>
            <result column="createUser2" property="createUser" jdbcType="VARCHAR"/>
            <result column="createTime2" property="createTime" jdbcType="TIMESTAMP"/>
            <result column="modifyUser2" property="modifyUser" jdbcType="VARCHAR"/>
            <result column="modifyTime2" property="modifyTime" jdbcType="TIMESTAMP"/>
            <collection property="children" ofType="*.dataresource.entity.dataobject.MasterBusiness">
                <id column="businessId3" property="businessId" jdbcType="INTEGER"/>
                <result column="businessCode3" property="businessCode" jdbcType="VARCHAR"/>
                <result column="businessName3" property="businessName" jdbcType="VARCHAR"/>
                <result column="businessLevel3" property="businessLevel" jdbcType="VARCHAR"/>
                <result column="parentId3" property="parentId" jdbcType="VARCHAR"/>
                <result column="sort3" property="sort" jdbcType="VARCHAR"/>
                <result column="explain3" property="explain" jdbcType="VARCHAR"/>
                <result column="status3" property="status" jdbcType="INTEGER"/>
                <result column="createUser3" property="createUser" jdbcType="VARCHAR"/>
                <result column="createTime3" property="createTime" jdbcType="TIMESTAMP"/>
                <result column="modifyUser3" property="modifyUser" jdbcType="VARCHAR"/>
                <result column="modifyTime3" property="modifyTime" jdbcType="TIMESTAMP"/>
            collection>
        collection>
    resultMap>

    <select id="selectTree" resultMap="TreeResultMap">
        SELECT
            c1.businessId 'businessId1',
                c1.businessCode 'businessCode1',
                c1.businessName 'businessName1',
                c1.businessLevel 'businessLevel1',
                c1.parentId 'parentId1',
                c1.sort 'sort1',
                c1.`explain` 'explain1',
                c1.`status` 'status1',
                c1.createUser 'createUser1',
                c1.createTime 'createTime1',
                c1.modifyUser 'modifyUser1',
                c1.modifyTime 'modifyTime1',
                c2.businessId 'businessId2',
                c2.businessCode 'businessCode2',
                c2.businessName 'businessName2',
                c2.businessLevel 'businessLevel2',
                c2.parentId 'parentId2',
                c2.sort 'sort2',
                c2.`explain` 'explain2',
                c2.`status` 'status2',
                c2.createUser 'createUser2',
                c2.createTime 'createTime2',
                c2.modifyUser 'modifyUser2',
                c2.modifyTime 'modifyTime2',
                c3.businessId 'businessId3',
                c3.businessCode 'businessCode3',
                c3.businessName 'businessName3',
                c3.businessLevel 'businessLevel3',
                c3.parentId 'parentId3',
                c3.sort 'sort3',
                c3.`explain` 'explain3',
                c3.`status` 'status',
                c3.createUser 'createUser3',
                c3.createTime 'createTime3',
                c3.modifyUser 'modifyUser3',
                c3.modifyTime 'modifyTime3'
        FROM
                ( SELECT * FROM master_business WHERE `status` = 1 ) c1
                    LEFT JOIN ( SELECT * FROM master_business WHERE `status` = 1 ) c2 ON c2.parentId = c1.businessId
                    LEFT JOIN ( SELECT * FROM master_business WHERE `status` = 1 ) c3 ON c3.parentId = c2.businessId
        WHERE
            c1.businessLevel = 1
    select>

1.4在bll中建立业务接口

package *.dataresource.bll;

public interface IMasterBusinessService {//查询树
    List selectTree();
}

1.5在impl实现业务接口

package *.dataresource.bll.impl;

@Service
public class MasterBusinessService extends BaseService implements IMasterBusinessService {

    @Autowired
    private IMasterBusinessRepository masterBusinessRepository;
//查询树
    @Override
    public List selectTree() {
        return masterBusinessRepository.selectTree();
    }


}

1.6在controller中获取路由与设置数据

package *.dataresource.controller;

@RestController
@RequestMapping("masterBusiness")
public class MasterBusinessController extends BaseController {

    @Autowired
    private IMasterBusinessService masterBusinessService;
//查询树
    @GetMapping("/selectAll")
    public List selectMasterBusiness()throws Exception{
        return masterBusinessService.selectTree();
    }

}  

1.7路由访问：

{{host}}/masterBusiness/selectAll

二、后续更新无限级分类