SpringBoot和Mybatis配置多数据源连接多个数据库

目前业界操作数据库的框架一般是Mybatis，但在很多业务场景下，我们需要在一个工程里配置多个数据源来实现业务逻辑。在SpringBoot中也可以实现多数据源并配合Mybatis框架编写xml文件来执行SQL。在SpringBoot中，配置多数据源的方式十分便捷，

下面开始上代码：

• 在pom.xml文件中需要添加一些依赖

• <!-- Spring Boot Mybatis 依赖 -->
  <dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>1.2.0</version>
  </dependency>
  
  <!-- MySQL 连接驱动依赖 -->
  <dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.39</version>
  </dependency>
  
  <!-- Druid 数据连接池依赖 -->
  <dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.18</version>
  </dependency>

• application.properties 配置两个数据源配置

• # master 数据源配置
  master:
    datasource:
      url: jdbc:sqlserver://localhost:1433;DatabaseName=RYAccountsDB
      driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
      username: sa
      password: sa!@123
      initial-size: 1
      min-idle: 1
      max-active: 20
      test-on-borrow: true
      max-wait: 60000
      time-between-eviction-runs-millis: 60000
      min-evictable-idle-time-millis: 300000
      validation-query: SELECT 1 FROM DUAL
      test-While-Idle: true
      test-on-return: false
      pool-prepared-statements: false
      max-pool-prepared-statement-per-connection-size: 20
      filters: stat,wall,log4j,config
  # second 数据源配置
  second:
    datasource:
      url: jdbc:mysql://localhost:33306/game_score_log?serverTimezone=GMT&useUnicode=true&characterEncoding=utf8
      username: root
      password: 1q2w#E4r
      driver-class-name: com.mysql.cj.jdbc.Driver
      max-idle: 10
      max-wait: 10000
      min-idle: 5
      initial-size: 5
  
  #mybatis:
  #  type-aliases-package: com.cjrh.game_api.dao
  #  mapper-locations: classpath*:mapper/*.xml
  server:
    port: 7000

• 数据源配置

• 多数据源配置的时候注意，必须要有一个主数据源，即 MasterDataSourceConfig 配置
  
  @Primary 标志这个 Bean 如果在多个同类 Bean 候选时，该 Bean 优先被考虑。「多数据源配置的时候注意，必须要有一个主数据源，用 @Primary 标志该 Bean
  @MapperScan 扫描 Mapper 接口并容器管理，包路径精确到 master，为了和下面 cluster 数据源做到精确区分
  @Value 获取全局配置文件 application.properties 的 kv 配置,并自动装配sqlSessionFactoryRef 表示定义了 key ，表示一个唯一 SqlSessionFactory 实例
  
  作者：ChinaXieShuai
  链接：https://www.jianshu.com/p/735852145580
  来源：简书
  简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。

  MasterDataSourceConfig的代码：

• package com.cjrh.game_api.jdbc;
  
  import com.alibaba.druid.pool.DruidDataSource;
  import org.apache.ibatis.session.SqlSessionFactory;
  import org.mybatis.spring.SqlSessionFactoryBean;
  import org.mybatis.spring.annotation.MapperScan;
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.context.annotation.Primary;
  import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
  import org.springframework.jdbc.datasource.DataSourceTransactionManager;
  
  import javax.sql.DataSource;
  
  
  /**
   * @program: game_api
   * @description:
   * @author: Dading
   * @create: 2019-04-12 14:14
   * @version: 1.0
   **/
  @Configuration
  // 扫描 Mapper 接口并容器管理
  @MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
  public class MasterDataSourceConfig {
  
  
      // 精确到 master 目录，以便跟其他数据源隔离
      static final String PACKAGE = "com.cjrh.game_api.dao.master";
      static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";
  
      @Value("${master.datasource.url}")
      private String url;
  
      @Value("${master.datasource.username}")
      private String user;
  
      @Value("${master.datasource.password}")
      private String password;
  
      @Value("${master.datasource.driver-class-name}")
      private String driverClass;
  
      @Bean(name = "masterDataSource")
      @Primary
      public DataSource masterDataSource() {
          DruidDataSource dataSource = new DruidDataSource();
          dataSource.setDriverClassName(driverClass);
          dataSource.setUrl(url);
          dataSource.setUsername(user);
          dataSource.setPassword(password);
          return dataSource;
      }
  
      @Bean(name = "masterTransactionManager")
      @Primary
      public DataSourceTransactionManager masterTransactionManager() {
          return new DataSourceTransactionManager(masterDataSource());
      }
  
      @Bean(name = "masterSqlSessionFactory")
      @Primary
      public SqlSessionFactory masterSqlSessionFactory(@Qualifier("masterDataSource") DataSource masterDataSource)
              throws Exception {
          final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
          sessionFactory.setDataSource(masterDataSource);
          sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                  .getResources(MasterDataSourceConfig.MAPPER_LOCATION));
          return sessionFactory.getObject();
      }
  
  }

  第二个数据源SecondDataSourceConfig的配置如下:

• package com.cjrh.game_api.jdbc;
  
  import com.alibaba.druid.pool.DruidDataSource;
  import org.apache.ibatis.session.SqlSessionFactory;
  import org.mybatis.spring.SqlSessionFactoryBean;
  import org.mybatis.spring.annotation.MapperScan;
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.springframework.beans.factory.annotation.Value;
  import org.springframework.context.annotation.Bean;
  import org.springframework.context.annotation.Configuration;
  import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
  import org.springframework.jdbc.datasource.DataSourceTransactionManager;
  
  import javax.sql.DataSource;
  
  /**
   * @program: game_api
   * @description:
   * @author: Dading
   * @create: 2019-04-12 14:14
   * @version: 1.0
   **/
  @Configuration
  // 扫描 Mapper 接口并容器管理
  @MapperScan(basePackages = SecondDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "secondSqlSessionFactory")
  public class SecondDataSourceConfig {
  
      // 精确到 cluster 目录，以便跟其他数据源隔离
      static final String PACKAGE = "com.cjrh.game_api.dao.second";
      static final String MAPPER_LOCATION = "classpath:mapper/second/*.xml";
  
      @Value("${second.datasource.url}")
      private String url;
  
      @Value("${second.datasource.username}")
      private String user;
  
      @Value("${second.datasource.password}")
      private String password;
  
      @Value("${second.datasource.driver-class-name}")
      private String driverClass;
  
      @Bean(name = "secondDataSource")
      public DataSource clusterDataSource() {
          DruidDataSource dataSource = new DruidDataSource();
          dataSource.setDriverClassName(driverClass);
          dataSource.setUrl(url);
          dataSource.setUsername(user);
          dataSource.setPassword(password);
          return dataSource;
      }
  
      @Bean(name = "secondTransactionManager")
      public DataSourceTransactionManager clusterTransactionManager() {
          return new DataSourceTransactionManager(clusterDataSource());
      }
  
      @Bean(name = "secondSqlSessionFactory")
      public SqlSessionFactory clusterSqlSessionFactory(@Qualifier("secondDataSource") DataSource clusterDataSource)
              throws Exception {
          final SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean();
          sessionFactory.setDataSource(clusterDataSource);
          sessionFactory.setMapperLocations(new PathMatchingResourcePatternResolver()
                  .getResources(SecondDataSourceConfig.MAPPER_LOCATION));
          return sessionFactory.getObject();
      }
  }

  项目目录如下：

•