springboot整合mybatis（使用MyBatis Generator)

引入依赖

<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>1.3.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
</dependencies>

使用MyBatis Generator

添加Maven插件

<plugin>
    <groupId>org.mybatis.generator</groupId>
    <artifactId>mybatis-generator-maven-plugin</artifactId>
    <version>1.3.7</version>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
    </dependencies>
</plugin>

这里需要加上mysql驱动的依赖,我第一次没有加，然后自动生成就一直报错。

添加配置文件generatorConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
    
    <context id="DB2Tables" targetRuntime="MyBatis3">
        <commentGenerator>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true" />
        </commentGenerator>

        <!--数据库连接信息-->
        <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/ssmweb?useSSL=false&amp;serverTimezone=UTC"
                        userId="root"
                        password="123456">
        </jdbcConnection>

        <!--是否应强制对DECIMAL和NUMERIC字段使用java.math.BigDecimal-->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!--配置自动生成Model（entity)-->
        <javaModelGenerator targetPackage="com.example.demo.model" targetProject="E:\intellij_idea\liull\springbootmybatisdemo\src\main\java">
            <!--<property name="enableSubPackages" value="true" />-->
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!--配置自动生成Mapper映射文件-->
        <sqlMapGenerator targetPackage="mapper"  targetProject="E:\intellij_idea\liull\springbootmybatisdemo\src\main\resources">
        
        </sqlMapGenerator>

        <!--配置自动生成dao-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.example.demo.dao"  targetProject="E:\intellij_idea\liull\springbootmybatisdemo\src\main\java">
       
        </javaClientGenerator>

        <!--配置表信息及类信息-->
        <table schema="ssmweb" tableName="emp" domainObjectName="Emp" >
            <generatedKey column="emp_id" sqlStatement="MySql" identity="true" />
        </table>

    </context>
</generatorConfiguration>

这里注意：在上面pom.xml中配置的mybatis-generator-maven-plugin插件，是默认加载/src/main/resources/目录下名为generatorConfig.xml。

运行插件

双击插件即可运行。

运行后目录：

 正式整合mybatis

配置application.yml

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ssmweb?useSSL=false&serverTimezone=UTC
    username: root
    password: 123456

#mybatis配置
mybatis:
  mapper-locations: classpath:mapper/*.xml

需要配置mapper映射文件位置，不然映射类无法找到映射文件位置，运行会报错。

扫描映射类

在springboot启动类上添加@MapperScan注解

@MapperScan(basePackages = {"com.example.demo.dao"})
@SpringBootApplication
public class SpringbootmybatisdemoApplication {

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

测试

service:

@Service
public class EmpService {
    @Autowired
    private EmpMapper empMapper;

    public List<Emp> getAll(){
        return empMapper.selectByExample(null);
    }
}

controller：

@RestController
public class EmpController {

    @Autowired
    private EmpService empService;

    @GetMapping("/emps")
    public List<Emp> getAll(){
        return empService.getAll();
    }

}

结果：