SpringBoot配置雙數據源

一、搭建springboot項目

二、添加依賴

<dependencies>
    <!--web服務-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--測試-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!--mybatis驅動-->
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.1</version>
    </dependency>
    <!--mysql驅動-->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <!--druid連接池-->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.1.24</version>
    </dependency>
    <!--lombok插件-->
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>

  	<!--數據實體類轉化-->
    <dependency>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct-jdk8</artifactId>
        <version>1.2.0.Final</version>
    </dependency>
    <dependency>
        <groupId>org.mapstruct</groupId>
        <artifactId>mapstruct-processor</artifactId>
        <version>1.2.0.Final</version>
    </dependency>
		<!--aop依賴，事務所需要-->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-aop</artifactId>
    </dependency>
</dependencies>

三、配置數據源

spring:
  datasource:
    master:
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: root
      url: jdbc:mysql://localhost:3306/sys_user?serverTimezone=UTC&autoReconnect=true&useUnicode=true&characterEncoding=utf8&useSSL=false&allowMultiQueries=true
      type: com.alibaba.druid.pool.DruidDataSource
    second:
      driver-class-name: com.mysql.jdbc.Driver
      username: root
      password: root
      url: jdbc:mysql://localhost:3306/t_sys_user?serverTimezone=UTC&autoReconnect=true&useUnicode=true&characterEncoding=utf8&useSSL=false&allowMultiQueries=true
      type: com.alibaba.druid.pool.DruidDataSource

#mybatis:
  #config‐location: classpath:mybatis/mybatis‐config.xml  #指定全局配置文件的位置
  #mapper‐locations: classpath:mapper/*.xml

logging:
  path: ./data_migration
  level:
    root: INFO
    com.cxqy.data: DEBUG

四、編寫數據源配置類

1、主數據源配置類 MasterDataSourceConfig

Configuration
@MapperScan(basePackages = MasterDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "masterSqlSessionFactory")
public class MasterDataSourceConfig {

    // 精確到 master 目錄，以便跟其他數據源隔離
    static final String PACKAGE = "com.cxqy.data.dao.master";
    static final String MAPPER_LOCATION = "classpath:mapper/master/*.xml";

    @Value("${spring.datasource.master.url}")
    private String url;

    @Value("${spring.datasource.master.username}")
    private String user;

    @Value("${spring.datasource.master.password}")
    private String password;

    @Value("${spring.datasource.master.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();
    }
}

2、副數據源配置類 SecondDataSourceConfig

@Configuration
@MapperScan(basePackages = SecondDataSourceConfig.PACKAGE, sqlSessionFactoryRef = "secondSqlSessionFactory")
public class SecondDataSourceConfig {

    // 精確到 cluster 目錄，以便跟其他數據源隔離
    static final String PACKAGE = "com.cxqy.data.dao.second";
    static final String MAPPER_LOCATION = "classpath:mapper/second/*.xml";

    @Value("${spring.datasource.second.url}")
    private String url;

    @Value("${spring.datasource.second.username}")
    private String user;

    @Value("${spring.datasource.second.password}")
    private String password;

    @Value("${spring.datasource.second.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();
    }
}

此時可以連接兩個數據源進行業務編寫。

注意避坑

在雙數據源的情況下，事務可能會失效，這時候需要指定那一個數據庫的操作需要進行事務，指定數據庫事務名在配置類中。

1、在啟動類BootdoApplication上添加@EnableTransactionManagement 注解

2、在service層添加@Transactional注解

@Transactional(readOnly = true,rollbackFor = Exception.class,transactionManager = "secondTransactionManager",isolation = Isolation.READ_UNCOMMITTED,propagation = Propagation.REQUIRED)

3、查看置頂數據庫事務名，在數據源配置類中查看