數據庫引擎不支持事務
在MySQL數據庫中有幾種引擎(InnoDB,MyISAM,Memory等等),僅僅InnoDB支持事務,如果數據庫底層都不支持事務的話,那么再怎么折騰都是白搭.
@transactional加在private方法上
@Transactional只能加在public方法上,如果需要在private方法中加入事務,可以使用Aspect配transactionManager使用.
本類方法調本類另一個方法
例如:
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@Servicepublic class UserServiceImpl implements UserService { @Transactional public void update(User user) { //check updateUserInfo(user); } @Transactional(propagation = Propagation.REQUIRES_NEW) public void updateUser(User user) { // update user }} |
@Transactional(propagation = Propagation.REQUIRES_NEW)是無效的,在Spring中是使用代理的方式實現事務,發生自身調用的時候,沒有經過Spring的代理,自然事務失效.
不支持事務
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@Servicepublic class UserServiceImpl implements UserService { @Transactional(propagation = Propagation.NOT_SUPPORTED) public void update(User user) { //do some action }} |
@Transactional(propagation = Propagation.NOT_SUPPORTED)表示如果當前存在事務就掛起,以沒有事務的方式運行,主動不支持事務了,那么再怎么操作也是白搭. 此處貼下Spring的傳播行為:
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/** * Support a current transaction, create a new one if none exists. * Analogous to EJB transaction attribute of the same name. * <p>This is the default setting of a transaction annotation. */REQUIRED(TransactionDefinition.PROPAGATION_REQUIRED),/** * Support a current transaction, execute non-transactionally if none exists. * Analogous to EJB transaction attribute of the same name. * <p>Note: For transaction managers with transaction synchronization, * PROPAGATION_SUPPORTS is slightly different from no transaction at all, * as it defines a transaction scope that synchronization will apply for. * As a consequence, the same resources (JDBC Connection, Hibernate Session, etc) * will be shared for the entire specified scope. Note that this depends on * the actual synchronization configuration of the transaction manager. * @see org.springframework.transaction.support.AbstractPlatformTransactionManager#setTransactionSynchronization */SUPPORTS(TransactionDefinition.PROPAGATION_SUPPORTS),/** * Support a current transaction, throw an exception if none exists. * Analogous to EJB transaction attribute of the same name. */MANDATORY(TransactionDefinition.PROPAGATION_MANDATORY),/** * Create a new transaction, and suspend the current transaction if one exists. * Analogous to the EJB transaction attribute of the same name. * <p><b>NOTE:</b> Actual transaction suspension will not work out-of-the-box * on all transaction managers. This in particular applies to * {@link org.springframework.transaction.jta.JtaTransactionManager}, * which requires the {@code javax.transaction.TransactionManager} to be * made available to it (which is server-specific in standard Java EE). * @see org.springframework.transaction.jta.JtaTransactionManager#setTransactionManager */REQUIRES_NEW(TransactionDefinition.PROPAGATION_REQUIRES_NEW),/** * Execute non-transactionally, suspend the current transaction if one exists. * Analogous to EJB transaction attribute of the same name. * <p><b>NOTE:</b> Actual transaction suspension will not work out-of-the-box * on all transaction managers. This in particular applies to * {@link org.springframework.transaction.jta.JtaTransactionManager}, * which requires the {@code javax.transaction.TransactionManager} to be * made available to it (which is server-specific in standard Java EE). * @see org.springframework.transaction.jta.JtaTransactionManager#setTransactionManager */NOT_SUPPORTED(TransactionDefinition.PROPAGATION_NOT_SUPPORTED),/** * Execute non-transactionally, throw an exception if a transaction exists. * Analogous to EJB transaction attribute of the same name. */NEVER(TransactionDefinition.PROPAGATION_NEVER),/** * Execute within a nested transaction if a current transaction exists, * behave like PROPAGATION_REQUIRED else. There is no analogous feature in EJB. * <p>Note: Actual creation of a nested transaction will only work on specific * transaction managers. Out of the box, this only applies to the JDBC * DataSourceTransactionManager when working on a JDBC 3.0 driver. * Some JTA providers might support nested transactions as well. * @see org.springframework.jdbc.datasource.DataSourceTransactionManager */NESTED(TransactionDefinition.PROPAGATION_NESTED); |
異常被catch
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@Servicepublic class UserServiceImpl implements UserService { @Transactional public void update(User user) { try{ }catch(Exception e){ log.error(e.getMessage(),e); } }} |
觸發回滾的操作是被接收到異常,一般我們會在@Transactional后面加上rollbackFor或者noRollbackForClassName來指明觸發回滾的異常,但是如果在代碼中給catch了異常,那么對于Spring代理來說就這個方法從頭到尾都沒有問題,自然不會觸發回滾.
異常類型錯誤
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@Servicepublic class UserServiceImpl implements UserService { @Transactional public void update(User user) { try{ }catch(Exception e){ log.error(e.getMessage(),e); throw new Exception(e.getMessage()); } }} |
以上方式throw new Exception(e.getMessage());事務也是無效的,主要原因是事務回滾的條件是throw 運行時異常(RunTimeException).如果需要其他異常也回滾,需要在@Transactional后面加上rollbackFor或者noRollbackForClassName來指明觸發回滾的異常.
沒有被Spring管理
不在Spring環境下,自然不受Spring的管理,事務管理器也當然失去了作用.
沒有配置TransactionManager
需要對當前數據源配置事務管理器,尤其是在多數據源的情況下.
以上就是Spring事務失效的幾種原因的詳細內容，更多關于Spring事務失效的資料請關注服務器之家其它相關文章！
原文鏈接：https://www.bianxiaofeng.com/article/77
