介绍
参考：http://www.yanglajiao.com/article/gaoshili001/79378902
原理请参考另外一篇文章：解决多数据源动态切换事务问题】Spring Mybatis 事务管理器源码
网上好多的springboot的事务都是瞎扯，根本不起作用，后来通过各种渠道查证，springboot的声明式事务需要重写Transaction，那么我们来解决多数据源动态切换事务的问题
核心方法：
private void openMainConnection() throws SQLException {
this.mainConnection = DataSourceUtils.getConnection(this.dataSource)
}直接上代码
CiweiSqlSessionFactory
/**
* 配置sqlSessionFactory
*/
@Configuration
@Slf4j
public class CiweiSqlSessionFactory {
@Autowired
DataSourceConfiguration.DynamicDataSource dataSource;
@Bean
public SqlSessionFactory sqlSessionFactory() {
log.info("-------------------- sqlSessionFactory init ---------------------");
try {
// SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
MybatisSqlSessionFactoryBean sessionFactoryB= new MybatisSqlSessionFactoryBean();
sessionFactorttoryBean.setDataSource(dataSource);
sessionFactoryBean.setTransactionFactory(new MultiDataSourceTransactionFactory());
// 读取配置
sessionFactoryBean.setTypeAliasesPackage("com.example.apollodynamicdatasource.entity");
//设置mapper.xml文件所在位置
Resource[] resources = new PathMatchingResourcePatternResolver().getResources("classpath*:/mapper/*.xml");
sessionFactoryBean.setMapperLocations(resources);
return sessionFactoryBean.getObject();
} catch (IOException e) {
log.error("mybatis resolver mapper*xml is error",e);
return null;
} catch (Exception e) {
log.error("mybatis sqlSessionFactoryBean create error",e);
return null;
}
}
}MultiDataSourceTransaction
/**
* 多数据源切换的支持事务
*/
public class MultiDataSourceTransaction implements Transaction {
private static final Log LOGGER = LogFactory.getLog(MultiDataSourceTransaction.class);
private final DataSource dataSource;
private Connection mainConnection;
private String mainDatabaseIdentification;
private ConcurrentMap<String, Connection> otherConnectionMap;
private boolean isConnectionTransactional;
private boolean autoCommit;
public MultiDataSourceTransaction(DataSource dataSource) {
notNull(dataSource, "No DataSource specified");
this.dataSource = dataSource;
otherConnectionMap = new ConcurrentHashMap<>();
mainDatabaseIdentification = DynamicDataSourceContextHolder.getDataSourceKey();
}
/**
* {@inheritDoc}
*/
@Override
public Connection getConnection() throws SQLException {
String databaseIdentification = DynamicDataSourceContextHolder.getDataSourceKey();
if (databaseIdentification.equals(mainDatabaseIdentification)) {
if (mainConnection != null) return mainConnection;
else {
openMainConnection();
mainDatabaseIdentification = databaseIdentification;
return mainConnection;
}
} else {
if (!otherConnectionMap.containsKey(databaseIdentification)) {
try {
Connection conn = dataSource.getConnection();
otherConnectionMap.put(databaseIdentification, conn);
} catch (SQLException ex) {
throw new CannotGetJdbcCoot get JDBC Connection", ex);
}
}
retu }
r }
}
}
return otherConnectionMap.get(databaseIdentification);
}
}
private void openMainConnection() throws SQLException {
this.mainConnection = DataSourceUtils.getConnection(this.dataSource);
this.autoCommit = this.mainConnection.getAutoCommit();
// this.isConnectionTransactional = DataSourceUtils.isConnectionTransactional(this.mainConnection, this.dataSource);
this.isConnectionTransactional = false;
if (LOGGER.isDebugEnabled()) {
LOGGER.debug(
"JDBC Connection ["
+ this.mainConnection
+ "] will"
+ (this.isConnectionTransactional ? " " : " not ")
+ "be managed by Spring");
}
}
/**
* {@inheritDoc}
*/
@Override
public void commit() throws SQLException {
if (this.mainConnection != null && !this.isConnectionTransactional && !this.autoCommit) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Committing JDBC Connection [" + this.mainConnection + "]");
}
this.mainConnection.commit();
for (Connection connection : otherConnectionMap.values()) {
connection.commit();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void rollback() throws SQLException {
if (this.mainConnection != null && !this.isConnectionTransactional && !this.autoCommit) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Rolling back JDBC Connection [" + this.mainConnection + "]");
}
this.mainConnection.rollback();
for (Connection connection : otherConnectionMap.values()) {
connection.rollback();
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void close() throws SQLException {
DataSourceUtils.releaseConnection(this.mainConnection, this.dataSource);
for (Connection connection : otherConnectionMap.values()) {
DataSourceUtils.releaseConnection(connection, this.dataSource);
}
}
@Override
public Integer getTimeout() throws SQLException {
return null;
}
}MultiDataSourceTransactionFactory
/**
* 支持Service内多数据源切换的Factory
*/
public class MultiDataSourceTransactionFactory extends SpringManagedTransactionFactory {
@Override
public Transaction newTransaction(DataSource dataSource, TransactionIsolationLevel level, boolean autoCommit) {
return new MultiDataSourceTransaction(dataSource);
}
}最后在代码中引入
@EnableTransactionManagement
@Transactional(propagation = Propagation.REQUIRED, rollbackFor = Throwable.class)需要注意的是：
在spring的文档中说道，spring声明式事务管理默认对非检查型异常和运行时异常进行事务回滚，而对检查型异常（try catch）则不进行回滚操作：
故而如果异常被try｛｝catch｛｝了，事务就不回滚了，如果想让事务回滚必须再往外抛try｛｝catch｛throw Exception｝
总结
代码必须关闭自动提交 关闭自动提交会根据代码手动控制提交 回滚的话也是代码中控制
dataSource.setAutoCommit(false);
