SpringBoot使用mybatis-plus配置多个数据源，实现项目中从两个不同的数据库读取数据

1、添加依赖包

<properties>
    <java.version>1.8</java.version>
    <mybatis.version>2.1.2</mybatis.version>
    <mybatis.plugin.version>3.4.3</mybatis.plugin.version>
    <pagehelper.version>1.2.13</pagehelper.version>
</properties>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>${mybatis.version}</version>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>${mybatis.plugin.version}</version>
</dependency>
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>${pagehelper.version}</version>
</dependency>

2、禁止SpringBoot自动配置数据源

在启动类注解上添加exclude参数

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class DemoApplication {

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

}

3、配置文件application.yml添加数据库信息

spring:
  datasource:
    db1:
      type: com.zaxxer.hikari.HikariDataSource
      driverClassName: com.mysql.cj.jdbc.Driver
      jdbcUrl: jdbc:mysql://172.16.253.52:3306/aaa?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=CONVERT_TO_NULL&useSSL=true&serverTimezone=GMT%2B8
      username: root
      password: root
    db2:
      type: com.zaxxer.hikari.HikariDataSource
      driverClassName: com.mysql.cj.jdbc.Driver
      jdbcUrl: jdbc:mysql://172.16.253.55:3306/bbb?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=CONVERT_TO_NULL&useSSL=true&serverTimezone=GMT%2B8
      username: root
      password: root

4、代码中配置db1和db2的数据源

新建类DataSourceConfig1

配置MapperLocation路径和MapperScan扫描路径

@Slf4j
@Configuration
@MapperScan(basePackages = "com.demo.mapper.db1.**", sqlSessionFactoryRef = "sqlSessionFactoryDB1")
public class DataSourceConfig1 {
    
    @Primary
    @Bean(name = "dataSourceDB1")
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource dataSource() {
        return DataSourceBuilder.create().type(HikariDataSource.class)
                .build();
    }

    @Bean(name = "sqlSessionFactoryDB1")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSourceDB1") DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/db1/*.xml"));
        log.info("------dataSource db12 配置成功");
        return sessionFactoryBean.getObject();
    }

    @Bean(name = "sqlSessionTemplateDB1")
    public SqlSessionTemplate sqlSessionFactoryTemplate(@Qualifier("sqlSessionFactoryDB1") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Bean(name = "txManagerDB1")
    public PlatformTransactionManager txManager(@Qualifier("dataSourceDB1") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

新建类DataSourceConfig2

@Slf4j
@Configuration
@MapperScan(basePackages = "com.demo.mapper.db2.**", sqlSessionFactoryRef = "sqlSessionFactoryDB2")
public class DataSourceConfig2 {
    
    @Primary
    @Bean(name = "dataSourceDB2")
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource dataSource() {
        return DataSourceBuilder.create().type(HikariDataSource.class)
                .build();
    }

    @Bean(name = "sqlSessionFactoryDB2")
    public SqlSessionFactory sqlSessionFactory(@Qualifier("dataSourceDB2") DataSource dataSource) throws Exception {
        MybatisSqlSessionFactoryBean sessionFactoryBean = new MybatisSqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        sessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver()
                .getResources("classpath*:mapper/db2/*.xml"));
        log.info("------dataSource db2 配置成功");
        return sessionFactoryBean.getObject();
    }

    @Bean(name = "sqlSessionTemplateDB2")
    public SqlSessionTemplate sqlSessionFactoryTemplate(@Qualifier("sqlSessionFactoryDB2") SqlSessionFactory sqlSessionFactory) {
        return new SqlSessionTemplate(sqlSessionFactory);
    }

    @Bean(name = "txManagerDB2")
    public PlatformTransactionManager txManager(@Qualifier("dataSourceDB2") DataSource dataSource) {
        return new DataSourceTransactionManager(dataSource);
    }
}

至此配置完成