SpringBoot第二节(SpringBoot整合Mybatis)

1.创建Spring Initiallizr项目

一直点击下一步

2.引入依赖

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
 
        <!--引入springboot-mybatis的依赖 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>
        <!--MySQL的依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.32</version>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    </dependencies>

3.创建resources文件夹

4.编写application.properties

spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql:///invoicingsystem
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
 
mybatis.mapper-locations=mapper/*.xml
mybatis.type-aliases-package=com.example.entity

application.properties文件里前缀为Spring.datasource  以及一些包的名字

5.编写Users实体类

6.创建IUsersDao接口

@Repository("iUsersDao")
public interface IUsersDao {
    //登录
    Users getlogin(@Param("userName") String userName, @Param("password") String password);
 
    //查看
    List<Users> getAll();
}

7.编写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">
<!--namespace需要指向接口全路径-->
<mapper namespace="com.example.dao.IUsersDao">
    <!--登录-->
    <select id="getlogin" resultType="com.example.entity.Users">
      SELECT * FROM users WHERE userName=#{userName} AND PASSWORD=#{password}
    </select>
 
    <!--查询用户-->
    <select id="getAll" resultType="Users">
        select * from users
    </select>
</mapper>

8.编写IUsersService

public interface IUsersService {
    //登录
    Users getlogin(String userName, String password);
 
    //查看
    List<Users> getAll();
}

9.编写IUsersServiceImpl实现类

@Service("iUsersService")
public class IUsersServiceImpl implements IUsersService {
    @Resource(name = "iUsersDao")
    private IUsersDao iUsersDao;
 
    @Override
    public Users getlogin(String userName, String password) {
        return iUsersDao.getlogin(userName,password);
    }
 
    @Override
    @Transactional
    public List<Users> getAll() {
        return iUsersDao.getAll();
    }
}

9.创建App启动类

@SpringBootApplication
@MapperScan("com.example.dao")
public class DemoApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
 
}

10.启动运行

补充：

在项目中application.properties还有另一种写法

application.yml

spring:
  datasource:
    username: root #必须以空格间隔
    password: root
    url: jdbc:mysql://localhost:3307/countrydb
    driver-class-name: com.mysql.jdbc.Driver
 
mybatis:
  mapper-locations: mapper/*.xml
  type-aliases-package: com.cmy.entity