从Controller-＞service-＞Impl-＞Mapper_serviceimpl<wmspurchasemapper, wmspurchase>-优快云博客

本文链接：https://blog.youkuaiyun.com/JiAngTxone/article/details/127702504

本文介绍了一个基于SpringBoot的简单应用案例，利用MyBatis框架完成用户的增删查改操作。通过Controller、Service、ServiceImpl及Mapper等组件展示了如何进行数据层交互，并给出了具体的实现代码。

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//Controller
@RestController
public class HelloController {    
@Autowired
private UserService userService;
@GetMapping("listnew")
    public List<User> listdemo(){
        return userService.listAll();
    }
}

//Service

@Service
public interface UserService extends IService<User> {
    List<User> listAll();
}

//ServiceImpl

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User>
        implements UserService{

    @Autowired
    private UserMapper userMapper;
    @Override
    public List<User> listAll() {
        return userMapper.ListAll();
    }
}

//Mapper 使用了Mybatise 继承了BaseMapper

@Repository
@Mapper
public interface UserMapper extends BaseMapper<User> {

    List<User> ListAll();//ListAll对应mapper文件中接口
}

//Mapper.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">
<!--绑定一个对应的Dao、Mapper接口-->
<mapper namespace="com.huang.wms.mapper.UserMapper">
    <!--    查询语句-->
    <select id="ListAll" resultType="com.huang.wms.entity.User">
        select * from wms_user;
    </select>
</mapper>