springboot 动态数据源的实现方法(Mybatis+Druid)

@Configuration
@MapperScan(basePackages = "com.goofly.test1", sqlSessionTemplateRef = "test1SqlSessionTemplate")
public class DataSource1Config1 {

  @Bean(name = "dataSource1")
  @ConfigurationProperties(prefix = "spring.datasource.test1")
  @Primary
  public DataSource testDataSource() {
    return DataSourceBuilder.create().build();
  }
  // .....略

}

@Configuration
@MapperScan(basePackages = "com.goofly.test2", sqlSessionTemplateRef = "test1SqlSessionTemplate")
public class DataSourceConfig2 {

  @Bean(name = "dataSource2")
  @ConfigurationProperties(prefix = "spring.datasource.test2")
  @Primary
  public DataSource testDataSource() {
    return DataSourceBuilder.create().build();
  }
  // .....略

}

public class DynamicRoutingDataSource extends AbstractRoutingDataSource {
  private static final Logger log = Logger.getLogger(DynamicRoutingDataSource.class);
  
  @Override
  protected Object determineCurrentLookupKey() {
    //从ThreadLocal中取值
    return DynamicDataSourceContextHolder.get();
  }
}

public abstract class AbstractRoutingDataSource extends AbstractDataSource implements InitializingBean {
  
  private Map<Object, Object> targetDataSources;
  private Object defaultTargetDataSource;
  private boolean lenientFallback = true;
  private DataSourceLookup dataSourceLookup = new JndiDataSourceLookup();
  private Map<Object, DataSource> resolvedDataSources;
  private DataSource resolvedDefaultDataSource;
  
    protected DataSource determineTargetDataSource() {
    Assert.notNull(this.resolvedDataSources, "DataSource router not initialized");
    Object lookupKey = determineCurrentLookupKey();
    DataSource dataSource = this.resolvedDataSources.get(lookupKey);
    if (dataSource == null && (this.lenientFallback || lookupKey == null)) {
      dataSource = this.resolvedDefaultDataSource;
    }
    if (dataSource == null) {
      throw new IllegalStateException("Cannot determine target DataSource for lookup key [" + lookupKey + "]");
    }
    return dataSource;
  }

  /**
   * Determine the current lookup key. This will typically be
   * implemented to check a thread-bound transaction context.
   * <p>Allows for arbitrary keys. The returned key needs
   * to match the stored lookup key type, as resolved by the
   * {@link #resolveSpecifiedLookupKey} method.
   */
  protected abstract Object determineCurrentLookupKey();
  
  //........略

public class JndiDataSourceLookup extends JndiLocatorSupport implements DataSourceLookup {

  public JndiDataSourceLookup() {
    setResourceRef(true);
  }

  @Override
  public DataSource getDataSource(String dataSourceName) throws DataSourceLookupFailureException {
    try {
      return lookup(dataSourceName, DataSource.class);
    }
    catch (NamingException ex) {
      throw new DataSourceLookupFailureException(
          "Failed to look up JNDI DataSource with name '" + dataSourceName + "'", ex);
    }
  }

}

# db1
spring.datasource.master.url = jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.master.username = root
spring.datasource.master.password = 123456
spring.datasource.master.driverClassName = com.mysql.jdbc.Driver
spring.datasource.master.validationQuery = true
spring.datasource.master.testOnBorrow = true
## db2
spring.datasource.slave.url = jdbc:mysql://127.0.0.1:3306/test1?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.slave.username = root
spring.datasource.slave.password = 123456
spring.datasource.slave.driverClassName = com.mysql.jdbc.Driver
spring.datasource.slave.validationQuery = true
spring.datasource.slave.testOnBorrow = true

#主数据源名称
spring.maindb=master
#mapperper包路径
mapper.basePackages =com.btps.xli.multidb.demo.mapper

spring.datasource.master.url = jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.master.username = root
spring.datasource.master.password = 123456
spring.datasource.master.driverClassName = com.mysql.jdbc.Driver
spring.datasource.master.validationQuery = true
spring.datasource.master.testOnBorrow = true

# mapper包路径
mapper.basePackages = com.goofly.xli.multidb.demo.mapper
# 主数据源名称
spring.maindb=master

spring.datasource.url = jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username = root
spring.datasource.password = 123456
spring.datasource.driverClassName = com.mysql.jdbc.Driver
spring.datasource.validationQuery = true
spring.datasource.testOnBorrow = true

# mapper包路径
mapper.basePackages = com.goofly.xli.multidb.demo.mapper

Description:

The dependencies of some of the beans in the application context form a cycle:

  happinessController (field private com.db.service.HappinessService com.db.controller.HappinessController.happinessService)
   ↓
  happinessServiceImpl (field private com.db.mapper.MasterDao com.db.service.HappinessServiceImpl.masterDao)
   ↓
  masterDao defined in file [E:\GitRepository\framework-gray\test-db\target\classes\com\db\mapper\MasterDao.class]
   ↓
  sqlSessionFactory defined in class path resource [com/goofly/xli/datasource/core/DynamicDataSourceConfiguration.class]
┌─────┐
| dynamicDataSource defined in class path resource [com/goofly/xli/datasource/core/DynamicDataSourceConfiguration.class]
↑   ↓
| firstDataSource defined in class path resource [com/goofly/xli/datasource/core/DynamicDataSourceConfiguration.class]
↑   ↓
| dataSourceInitializer

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class DBMain {
  public static void main(String[] args) {
    SpringApplication.run(DBMain.class, args);
  }
}