springboot结合mybatis

Posted 2022-12-27 yanguobin

idea中新建springboot项目

pom.xml依赖部分如下

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.2</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>

    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.1</version>
    </dependency>
</dependencies>

 application.properties如下

spring.datasource.url=jdbc:mysql://localhost:3306/miaosha?useUnicode=true&characterEncoding=utf-8&allowMultiQueries=true&useSSL=false
spring.datasource.username=root
spring.datasource.password=123
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

 数据表内容如下

用户实体类如下

public class User 

    private int id;
    private String name;

    @Override
    public String toString() 
        return "User" +
                "id=" + id +
                ", name=‘" + name + ‘\\‘‘ +
                ‘‘;
    

    public int getId() 
        return id;
    

    public void setId(int id) 
        this.id = id;
    

    public String getName() 
        return name;
    

    public void setName(String name) 
        this.name = name;
    

dao层用户接口如下

@Mapper
public interface UserDao 

    @Select("select * from user where id = #id")
    public User hello(@Param("id")int id    );

@Mapper和@Select等注解都在mybatis-3.5.2.jar包下

注意依赖中还引入了mybatis-spring-boot-starter依赖，它会提供如下功能：

• 自动检测现有的DataSource
• 将创建并注册SqlSessionFactory的实例，该实例使用SqlSessionFactoryBean将该DataSource作为输入进行传递
• 将创建并注册从SqlSessionFactory中获取的SqlSessionTemplate的实例
• 自动扫描您的mappers，将它们链接到SqlSessionTemplate并将其注册到Spring上下文，以便将它们注入到您的bean中

测试

@Controller
public class UserController 

    @Autowired
    UserDao userDao;

    @RequestMapping("/get")
    @ResponseBody
    public String get()
        User user = userDao.hello(1);
        System.out.println(user);
        return "hello world";
    

可以成功获取