如题，升级了一下mybatis版本后出现循环引用的问题。
具体异常如下
***************************APPLICATION FAILED TO START***************************Description:The dependencies of some of the beans in the application context form a cycle: 略 ↓ sqlSessionFactory defined in class path resource [com/suike/config/database/MyBatisConfig.class]┌─────┐| dataSource defined in class path resource [com/suike/config/database/MyBatisConfig.class]↑ ↓| dataSourceDev defined in class path resource [com/suike/config/database/dataSource/DruidDBConfigDev.class]↑ ↓| dataSourceInitializer└─────┘然后抛出一堆的：org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSourceDev' defined in class path resource [xxx类]: Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSourceInitializer': Invocation of init method failed; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'dataSource': Requested bean is currently in creation: Is there an unresolvable circular reference?
我的配置一共3个，前两个是数据源，第3个是Mybatis的配置类
@Configurationpublic class DruidDBConfigDev { @Bean(name="dataSourceDev") public DruidDataSource dataSource(){ DruidDataSource datasource = new DruidDataSource(); //略 return datasource; }} @Configurationpublic class DruidDBConfigProd { @Bean(name="dataSourceProd") public DruidDataSource dataSource(){ DruidDataSource datasource = new DruidDataSource(); //略 return datasource; }} @Configuration() @MapperScan(value = "com.suike.mapper")public class MyBatisConfig { //重点在这个方法 @Bean @Primary public DynamicDataSource dataSource(@Qualifier("dataSourceDev") DataSource dataSourceDev, @Qualifier("dataSourceProd") DataSource dataSourceProd) { Map targetDataSources = new HashMap<>(); targetDataSources.put(DatabaseType.dataSourceDev, dataSourceDev); targetDataSources.put(DatabaseType.dataSourceProd, dataSourceProd); DynamicDataSource dataSource = new DynamicDataSource(); dataSource.setTargetDataSources(targetDataSources);// 该方法是AbstractRoutingDataSource的方法 dataSource.setDefaultTargetDataSource(dataSourceDev);// 默认的datasource设置为myTestDbDataSource return dataSource; } /** * 根据数据源创建SqlSessionFactory */ @Bean public SqlSessionFactory sqlSessionFactory(DynamicDataSource dataSource) throws Exception { SqlSessionFactoryBean sessionFactory = new SqlSessionFactoryBean(); sessionFactory.setDataSource(dataSource); return sessionFactory.getObject(); } @Bean public SqlSessionTemplate sqlSessionTemplate(SqlSessionFactory sqlSessionFactory) { return new SqlSessionTemplate(sqlSessionFactory); } /** * 配置事务管理器 */ @Bean public DataSourceTransactionManager transactionManager(DynamicDataSource dataSource) { return new DataSourceTransactionManager(dataSource); } @Bean public TransactionTemplate txTemplate(DataSourceTransactionManager transactionManager) { return new TransactionTemplate(transactionManager); }}
看完3个配置，再回过头来看异常信息
┌─────┐
| dataSource defined in class path resource [com/suike/config/database/MyBatisConfig.class] ↑ ↓ | dataSourceDev defined in class path resource [com/suike/config/database/dataSource/DruidDBConfigDev.class] ↑ ↓ | dataSourceInitializer └─────┘看起来意思就是MyBatisConfig需要依赖DruidDBConfigDev数据源，而DruidDBConfigDev数据源创建的时候又需要依赖这个dataSourceInitializer。
但是dataSourceInitializer又需要依赖MyBatisConfig
解决方案1：
不要把数据源注入spring,直接在配置类配置数据源的方法里new一个数据源
如：
/** * @Primary 指定在同一个接口有多个实现类可以注入的时候，默认选择哪一个，而不是让@Autowire注解报错（一般用于多数据源的情况下） * @Qualifier 根据名称进行注入，通常是在具有相同的多个类型的实例的一个注入（例如有多个DataSource类型的实例） */ @Bean @Primary public DynamicDataSource dataSource() { DruidDataSource datasource1 = new DruidDataSource(); datasource1.setUrl(""); datasource1.setUsername(""); datasource1.setPassword(""); datasource1.setDriverClassName("com.mysql.jdbc.Driver"); DruidDataSource datasource2 = new DruidDataSource(); //略 Map targetDataSources = new HashMap<>(); targetDataSources.put(DatabaseType.dataSourceDev, datasource1); targetDataSources.put(DatabaseType.dataSourceProd, datasource2); DynamicDataSource dataSource = new DynamicDataSource(); dataSource.setTargetDataSources(targetDataSources);// 该方法是AbstractRoutingDataSource的方法 dataSource.setDefaultTargetDataSource(datasource1);// 默认的datasource设置为myTestDbDataSource return dataSource; }
解决方案2（推荐）：
保持原来的配置，在Spring boot启动的时候排除DataSourceAutoConfiguration，并另外导入MyBatisConfig
@Import({MyBatisConfig.class})@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})public class App extends SpringBootServletInitializer { public static void main(String[] args) { SpringApplication.run(App.class, args); }}