Mybatis中mapper继承

迈不过友情╰ 2022-01-31 03:21 337阅读 0赞

## 前言 ##

#### [博主github][github] ####

#### [博主个人博客http://blog.healerjean.com][http_blog.healerjean.com] ####

### 1、mapper ###

#### 1.1、父mapper ####

public interface FatherMapper { 
    
        DemoEntity findById1();
    
        DemoEntity extendMethod();
    
    }

#### 1.2、子mapper ####

public interface SonMapper extends FatherMapper{ 
    
        /** * 覆盖父类的方法，这里的id为4 * @return */
        DemoEntity extendMethod();
    
        DemoEntity findById3();
    
    }

### 2、xml ###

#### 2.1、父xml ####

<?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.hlj.dao.mybatis.demo.FatherMapper">
    
        <select id="findById1" resultType="com.hlj.entity.db.demo.DemoEntity">
            select * from demo_entity d where d.id = 1
        </select>
    
        <select id="extendMethod" resultType="com.hlj.entity.db.demo.DemoEntity">
            select * from demo_entity d where d.id = 2
        </select>
    
    </mapper>

#### 2.2、子xml ####

<?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.hlj.dao.mybatis.demo.SonMapper">
    
        <select id="extendMethod" resultType="com.hlj.entity.db.demo.DemoEntity">
            select * from demo_entity d where d.id = 4
        </select>
    
        <select id="findById3" resultType="com.hlj.entity.db.demo.DemoEntity">
            select * from demo_entity d where d.id = 3
        </select>
    
    </mapper>

### 3、service ###

public interface DemoEntityService { 
    
        List<DemoEntity> mapperExtend();
    }
    
    
    
    
    @Service
    @Slf4j
    public class DemoEntityServiceImpl implements DemoEntityService { 
    
        @Resource
        private FatherMapper fatherMapper;
    
        @Resource
        private SonMapper sonMapper;
    
    
        @Override
        public List<DemoEntity> mapperExtend() { 
            List<DemoEntity> demoEntities = new ArrayList<>();
            demoEntities.add(fatherMapper.findById1());
            demoEntities.add(fatherMapper.extendMethod());
    
            demoEntities.add(sonMapper.findById1()); //继承的父类
            demoEntities.add(sonMapper.extendMethod());//重写的方法
            demoEntities.add(sonMapper.findById3());//自己的方法
    
            return demoEntities;
        }
    }

### 4、controller ###

@ApiResponses(value = { 
            @ApiResponse(code = 200, message = "访问正常"),
            @ApiResponse(code = 301, message = "逻辑错误"),
            @ApiResponse(code = 500, message = "系统错误"),
            @ApiResponse(code = 401, message = "未认证"),
            @ApiResponse(code = 403, message = "禁止访问"),
            @ApiResponse(code = 404, message = "url错误")
    })
    @Api(description = "demo控制器")
    @Controller
    @RequestMapping("mapper")
    public class DemoController { 
    
    
        @Autowired
        private DemoEntityService  demoEntityService;
    
        @ApiOperation(notes = "mapper继承",
                value = "mapper继承",
                consumes = MediaType.APPLICATION_FORM_URLENCODED_VALUE,
                produces = MediaType.APPLICATION_JSON_VALUE,
                response = DemoEntity.class)
        @GetMapping("extend")
        @ResponseBody
        public ResponseBean  mapperExtend(){ 
            try { 
                return ResponseBean.buildSuccess(demoEntityService.mapperExtend());
            }catch (AppException e){ 
                ExceptionLogUtils.log(e,this.getClass() );
                return  ResponseBean.buildFailure(e.getCode(),e.getMessage());
            }catch (Exception e){ 
                ExceptionLogUtils.log(e,this.getClass() );
                return  ResponseBean.buildFailure(e.getMessage());
            }
        }
    
    }

### 5、测试 ###

{ 
        "success": true,
        "result": [
            { 
                "id": 1,
                "name": "HealerJean",
                "age": null,
                "cdate": "2019-05-14T18:00:39.000+0000",
                "udate": "2019-05-14T10:00:39.000+0000"
            },
            { 
                "id": 2,
                "name": "DemoEntity(id=null, name=HealerJean, age=null, cdate=null, udate=null)1",
                "age": null,
                "cdate": "2019-05-14T18:00:39.000+0000",
                "udate": "2019-05-14T10:00:39.000+0000"
            },
            { 
                "id": 1,
                "name": "HealerJean",
                "age": null,
                "cdate": "2019-05-14T18:00:39.000+0000",
                "udate": "2019-05-14T10:00:39.000+0000"
            },
            { 
                "id": 4,
                "name": "DemoEntity(id=null, name=HealerJean, age=null, cdate=null, udate=null)1",
                "age": null,
                "cdate": "2019-05-14T18:01:05.000+0000",
                "udate": "2019-05-14T10:01:06.000+0000"
            },
            { 
                "id": 3,
                "name": "HealerJean",
                "age": null,
                "cdate": "2019-05-14T18:01:05.000+0000",
                "udate": "2019-05-14T10:01:06.000+0000"
            }
        ],
        "message": "",
        "code": "200",
        "date": "1557889965987"
    }

### [代码下载][Link 1] ###

![ContactAuthor][]

[github]: https://github.com/HealerJean
[http_blog.healerjean.com]: http://HealerJean.github.io
[Link 1]: https://github.com/HealerJean/hlj-maper-extend
[ContactAuthor]: /images/20220131/c7fe9def13b94c4790f0c6f8e270b3f4.png