Idea创建SpringBoot项目(集成MyBatis + MySQL)

1. 新建工程

1.1 Create New Project

1.2 选择 Spring Initializr 创建器和选择SDK版本

1.3 填写组织、项目名称和Java版本信息等

1.4 选择需要的依赖

1.5 填写项目、选择存储路径，然后点击finish

至此，项目已创建好。

1. 配置访问接口

2.1 新建 controller.HelloController 控制器文件

@RestController
public class HelloController {

    @RequestMapping(value = "/hi", method = RequestMethod.GET)
    public String sayHello() {
        return "Hi buddy, How're you today ? ";
    }
}

2.2 修改应用主入口文件MessageSystemApplication，注解添加(exclude = DataSourceAutoConfiguration.class)使其不需要配置数据库。最后如下

@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
public class MessageSystemApplication {

    public static void main(String[] args) {
        SpringApplication.run(MessageSystemApplication.class, args);
    }

}

2.3 启动应用，然后在浏览器访问：http://127.0.0.1:8080/hi，服务器相应并返回字符串，如下图：

1. 配置阿里云依赖库地址

<repositories>
        <repository>
            <id>alimaven</id>
            <name>Maven Aliyun Mirror</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

1. 配置 MyBatis 应用

4.1 pom.xml 添加依赖和配置

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>cn.longmaster</groupId>
    <artifactId>message-system</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>message-system</name>
    <description>MessageSystemproject for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>

    <dependencies>

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

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.1</version>
        </dependency>


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

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>

        <resources>
            <resource>
                <directory>src/main/resources</directory>
            </resource>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>cn/longmaster/messagesystem/mapper/xml/*.xml</include>
                </includes>
            </resource>
        </resources>
    </build>

<!--    配置阿里仓库-->
    <repositories>
        <repository>
            <id>alimaven</id>
            <name>Maven Aliyun Mirror</name>
            <url>https://maven.aliyun.com/repository/public</url>
            <releases>
                <enabled>true</enabled>
            </releases>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

    <pluginRepositories>
        <pluginRepository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/milestone</url>
        </pluginRepository>
    </pluginRepositories>

</project>

4.2 配置数据库连接
在resources目录下新建 application.yml 配置文件，并进行数据库配置如下

spring:
  datasource:
    url: jdbc:mysql://127.0.0.1:3306/db_ms?useUnicode=true&amp&characterEncoding=utf-8&serverTimezone=UTC #注意设置编码格式 #url
    username: root #用户名
    password: longmaster #密码
    driver-class-name: com.mysql.cj.jdbc.Driver #数据库链接驱动

mybatis:
  mapper-locations: classpath:cn/longmaster/messagesystem/mapper/xml/*.xml # 注意:一定要对应mapper映射xml文件的所在路径
  type-aliases-package: cn.longmaster.messagesystem.entity  # 注意:对应实体类的路径

4.3 新建实体类 entity.User

@Data
public class User {
    private int user_id;
    private String job_number;
    private String name;
    private String password;
    private Date birthday;
    private int use_state;
}

4.4 新建 mapper.UserMapper

@Repository
public interface UserMapper {
    /**
     * 新增职工信息
     * @param user
     * @return
     */
    int addUser(@Param("user") User user);
}

4.5 新建 xml， mapper.xml.UserMapper.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="cn.longmaster.messagesystem.mapper.UserMapper">

    <insert id="addUser" >
        INSERT INTO t_user(job_number, name, password, birthday, use_state) VALUES
        (#{user.job_number}, #{user.name}, #{user.password}, #{user.birthday}, 1)
    </insert>

</mapper>

4.6 新建服务类 service.UserService

@Service
public class UserService {
    @Autowired
    UserMapper userMapper;

    public String addUser(User user) {
        if (userMapper.addUser(user) > 0) {
            return "Add Success";
        } else {
            return "Add Fail";
        }
    }
}

4.7 控制器添加新增方法addUser:

@RestController
public class HelloController {

    @Autowired
    UserService userService;

    @RequestMapping(value = "/hi", method = RequestMethod.GET)
    public String sayHello() {
        return "Hi buddy, How're you today ? ";
    }

    @RequestMapping(value = "/addUser", method = RequestMethod.POST)
    public String addUser(@RequestBody User user) {
        return userService.addUser(user);
    }
}

4.8 应用入口类添加Mapper

@SpringBootApplication
@MapperScan("cn.longmaster.messagesystem.mapper")
public class MessageSystemApplication {

    public static void main(String[] args) {
        SpringApplication.run(MessageSystemApplication.class, args);
    }

}

至此，所有的配置完成。启动程序，通过POST发送添加请求，添加成功。如下图

数据库