SpringBoot+Mybatis实例（图文教程）

现在在公司主要还是做大数据平台的测试，而今天记录下SpringBoot整合Mybatis，好记性不如烂笔头。

废话不多说，开干。在网上找到一个不错的轮子。直接整

一、项目搭建

开始时确保具备以下条件：

jdk、IDEA、Maven、mysql

1、新建一个Spring Initializr项目

2、建文件结构选择jdk版本

3、选择依赖。注意spring boot 迭代到3开头了，这里选择默认的2.7.5，点击下一步

4、修改项目名，点击finish完成

5、完成后，看看pom.xml 依赖

代码：

<?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>2.7.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <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>2.2.2</version>
        </dependency>

        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
            <version>2.7.5</version>
        </dependency>
    </dependencies>

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

</project>

6、修改配置文件，在resources目录下新建两个yml文件application.yml和application-dev.yml文件

（注意，这里把原来的application.properties删掉采用yml格式，yml格式更简洁一些，这2种方式spring boot都支持）

这2个文件的意思是：

在项目中配置多套环境的配置方法。
因为现在一个项目有好多环境，开发环境，测试环境，UAT环境，准生产环境，生产环境，
每个环境的参数不同，所以我们就可以把每个环境的参数配置到yml文件中，
这样在想用哪个环境的时候只需要在主配置文件中将用的配置文件写上就行如application.yml

在Spring Boot中多环境配置文件名需要满足
application-{profile}.yml的格式，其中{profile}对应你的环境标识，比如：

application-dev.yml：开发环境
application-test.yml：测试环境
application-uat.yml：uat环境
application-prod.yml：生产环境
至于哪个具体的配置文件会被加载，需要在application.yml文件中通过
spring.profiles.active属性来设置，其值对应{profile}值。

application.yml：

spring:
  profiles:
    active: dev

application-dev.yml：

server:
  port: 8080

spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/books?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
    #driver-class-name: com.mysql.jdbc.Driver 这个驱动已经被弃用
    driver-class-name: com.mysql.cj.jdbc.Driver

mybatis:
  mapper-locations: classpath:mapping/*Mapping.xml
  type-aliases-package: com.example.entity
#showSql
logging:
  level:
    com:
      example:
        mapper : debug

把启动类文件移到com.example下

二、数据库设计

数据库建表语句

CREATE TABLE `user` (
  `id` int(32) NOT NULL AUTO_INCREMENT,
  `userName` varchar(32) NOT NULL,
  `passWord` varchar(50) NOT NULL,
  `realName` varchar(32) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

三、加入代码

创建包controller、entity、mapper、service。resources下创建mapping文件夹，用于写sql语句，也可以用注解的方式直接写在mapper文件里。下面直接贴代码

1、在controller包下新建UserController.java

UserController.java

package com.example.controller;

import com.example.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/testBoot")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("getUser/{id}")
    public String GetUser(@PathVariable int id){
        return userService.Sel(id).toString();
    }
}

2、在entity包下新建User.java

User.java

package com.example.entity;

public class User {
    private Integer id;
    private String userName;
    private String passWord;
    private String realName;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getPassWord() {
        return passWord;
    }

    public void setPassWord(String passWord) {
        this.passWord = passWord;
    }

    public String getRealName() {
        return realName;
    }

    public void setRealName(String realName) {
        this.realName = realName;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", userName='" + userName + '\'' +
                ", passWord='" + passWord + '\'' +
                ", realName='" + realName + '\'' +
                '}';
    }
}

3、在mapper包下新建UserMapper.java

UserMapper.java

package com.example.mapper;

import com.example.entity.User;
import org.springframework.stereotype.Repository;
@Repository
public interface UserMapper {

    User Sel(int id);
}

4、在service包下新建UserService.java

UserService.java

package com.example.service;

import com.example.entity.User;
import com.example.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {
    @Autowired
    UserMapper userMapper;

    public User Sel(int id) {
        return userMapper.Sel(id);
    }
}

5、在mapping文件夹新建UserMapping.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.example.mapper.UserMapper">

    <resultMap id="BaseResultMap" type="com.example.entity.User">
        <result column="id" jdbcType="INTEGER" property="id" />
        <result column="userName" jdbcType="VARCHAR" property="userName" />
        <result column="passWord" jdbcType="VARCHAR" property="passWord" />
        <result column="realName" jdbcType="VARCHAR" property="realName" />
    </resultMap>

    <select id="Sel" resultType="com.example.entity.User">
        select * from user where id = #{id}
    </select>

</mapper>

最终的项目框架结构：

7、在启动类里加上注解用于给出需要扫描的mapper文件路径

加入下面2行代码

package com.example;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan("com.example.mapper") //扫描的mapper
@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {

        SpringApplication.run(DemoApplication.class, args);
    }

}

8、启动。

9、日志打印：

D:\Java\jdk1.8.0_144\bin\java.exe -XX:TieredStopAtLevel=1 -noverify -Dspring.output.ansi.enabled=always -Dcom.sun.management.jmxremote -Dspring.jmx.enabled=true -Dspring.liveBeansView.mbeanDomain -Dspring.application.admin.enabled=true "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2020.1\lib\idea_rt.jar=52790:D:\Program Files\JetBrains\IntelliJ IDEA 2020.1\bin" -Dfile.encoding=UTF-8 -classpath D:\Java\jdk1.8.0_144\jre\lib\charsets.jar;D:\Java\jdk1.8.0_144\jre\lib\deploy.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\access-bridge-32.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\cldrdata.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\dnsns.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\jaccess.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\jfxrt.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\localedata.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\nashorn.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunec.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunjce_provider.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunmscapi.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\sunpkcs11.jar;D:\Java\jdk1.8.0_144\jre\lib\ext\zipfs.jar;D:\Java\jdk1.8.0_144\jre\lib\javaws.jar;D:\Java\jdk1.8.0_144\jre\lib\jce.jar;D:\Java\jdk1.8.0_144\jre\lib\jfr.jar;D:\Java\jdk1.8.0_144\jre\lib\jfxswt.jar;D:\Java\jdk1.8.0_144\jre\lib\jsse.jar;D:\Java\jdk1.8.0_144\jre\lib\management-agent.jar;D:\Java\jdk1.8.0_144\jre\lib\plugin.jar;D:\Java\jdk1.8.0_144\jre\lib\resources.jar;D:\Java\jdk1.8.0_144\jre\lib\rt.jar;E:\javaproject\demo\target\classes;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter-jdbc\2.7.5\spring-boot-starter-jdbc-2.7.5.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter\2.7.5\spring-boot-starter-2.7.5.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter-logging\2.7.5\spring-boot-starter-logging-2.7.5.jar;C:\Users\Administrator\.m2\repository\ch\qos\logback\logback-classic\1.2.11\logback-classic-1.2.11.jar;C:\Users\Administrator\.m2\repository\ch\qos\logback\logback-core\1.2.11\logback-core-1.2.11.jar;C:\Users\Administrator\.m2\repository\org\apache\logging\log4j\log4j-to-slf4j\2.17.2\log4j-to-slf4j-2.17.2.jar;C:\Users\Administrator\.m2\repository\org\apache\logging\log4j\log4j-api\2.17.2\log4j-api-2.17.2.jar;C:\Users\Administrator\.m2\repository\org\slf4j\jul-to-slf4j\1.7.36\jul-to-slf4j-1.7.36.jar;C:\Users\Administrator\.m2\repository\jakarta\annotation\jakarta.annotation-api\1.3.5\jakarta.annotation-api-1.3.5.jar;C:\Users\Administrator\.m2\repository\org\yaml\snakeyaml\1.30\snakeyaml-1.30.jar;C:\Users\Administrator\.m2\repository\com\zaxxer\HikariCP\4.0.3\HikariCP-4.0.3.jar;C:\Users\Administrator\.m2\repository\org\slf4j\slf4j-api\1.7.36\slf4j-api-1.7.36.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-jdbc\5.3.23\spring-jdbc-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-beans\5.3.23\spring-beans-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-tx\5.3.23\spring-tx-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter-web\2.7.5\spring-boot-starter-web-2.7.5.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter-json\2.7.5\spring-boot-starter-json-2.7.5.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\core\jackson-databind\2.13.4.2\jackson-databind-2.13.4.2.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\core\jackson-annotations\2.13.4\jackson-annotations-2.13.4.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\core\jackson-core\2.13.4\jackson-core-2.13.4.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.13.4\jackson-datatype-jdk8-2.13.4.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.13.4\jackson-datatype-jsr310-2.13.4.jar;C:\Users\Administrator\.m2\repository\com\fasterxml\jackson\module\jackson-module-parameter-names\2.13.4\jackson-module-parameter-names-2.13.4.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-starter-tomcat\2.7.5\spring-boot-starter-tomcat-2.7.5.jar;C:\Users\Administrator\.m2\repository\org\apache\tomcat\embed\tomcat-embed-core\9.0.68\tomcat-embed-core-9.0.68.jar;C:\Users\Administrator\.m2\repository\org\apache\tomcat\embed\tomcat-embed-el\9.0.68\tomcat-embed-el-9.0.68.jar;C:\Users\Administrator\.m2\repository\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.68\tomcat-embed-websocket-9.0.68.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-web\5.3.23\spring-web-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-webmvc\5.3.23\spring-webmvc-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-aop\5.3.23\spring-aop-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-context\5.3.23\spring-context-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-expression\5.3.23\spring-expression-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\mybatis\spring\boot\mybatis-spring-boot-starter\2.2.2\mybatis-spring-boot-starter-2.2.2.jar;C:\Users\Administrator\.m2\repository\org\mybatis\spring\boot\mybatis-spring-boot-autoconfigure\2.2.2\mybatis-spring-boot-autoconfigure-2.2.2.jar;C:\Users\Administrator\.m2\repository\org\mybatis\mybatis\3.5.9\mybatis-3.5.9.jar;C:\Users\Administrator\.m2\repository\org\mybatis\mybatis-spring\2.0.7\mybatis-spring-2.0.7.jar;C:\Users\Administrator\.m2\repository\com\mysql\mysql-connector-j\8.0.31\mysql-connector-j-8.0.31.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-core\5.3.23\spring-core-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\spring-jcl\5.3.23\spring-jcl-5.3.23.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot-autoconfigure\2.7.5\spring-boot-autoconfigure-2.7.5.jar;C:\Users\Administrator\.m2\repository\org\springframework\boot\spring-boot\2.7.5\spring-boot-2.7.5.jar com.example.DemoApplication

  .   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::                (v2.7.5)

2022-10-22 11:35:48.403  INFO 17520 --- [           main] com.example.DemoApplication              : Starting DemoApplication using Java 1.8.0_144 on HY-201709031002 with PID 17520 (E:\javaproject\demo\target\classes started by Administrator in E:\javaproject\demo)
2022-10-22 11:35:48.407  INFO 17520 --- [           main] com.example.DemoApplication              : The following 1 profile is active: "dev"
2022-10-22 11:35:50.263  INFO 17520 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat initialized with port(s): 8080 (http)
2022-10-22 11:35:50.277  INFO 17520 --- [           main] o.apache.catalina.core.StandardService   : Starting service [Tomcat]
2022-10-22 11:35:50.277  INFO 17520 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet engine: [Apache Tomcat/9.0.68]
2022-10-22 11:35:50.512  INFO 17520 --- [           main] o.a.c.c.C.[Tomcat].[localhost].[/]       : Initializing Spring embedded WebApplicationContext
2022-10-22 11:35:50.512  INFO 17520 --- [           main] w.s.c.ServletWebServerApplicationContext : Root WebApplicationContext: initialization completed in 1974 ms
2022-10-22 11:35:51.412  INFO 17520 --- [           main] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8080 (http) with context path ''
2022-10-22 11:35:51.428  INFO 17520 --- [           main] com.example.DemoApplication              : Started DemoApplication in 3.922 seconds (JVM running for 5.247)