Spring事务源码解析小结.doc

TransactionInterceptor 继承TransactionAspectSupport通过事务 TransactionInterceptor 事务拦截器生成目标Bean的代理对象TransactionInterceptor 事务拦截器（声明式事务）final TransactionAttribute txAttr =getTransactionAttributeSource().getTransactionAttribute(invocation.getMethod(), targetClass);/拦截到方法的事务属性txAttr 如：PROPAGATION_REQUIRED,ISOLATION_DEFAULTSpring 拦截器默认 事务属性 PROPAGATION_REQUIRED,ISOLATION_DEFAULTfinal String joinpointIdentification = methodIdentification(invocation.getMethod();通过ClassUtils.getQualifiedMethodName(method);获取拦截到的方法名称/在切面上添加事务的方法 jdk动态代理public Object invoke(final MethodInvocation invocation) throws Throwable / Work out the target class: may be null./ The TransactionAttributeSource should be passed the target class/ as well as the method, which may be from an interface.Class targetClass = (invocation.getThis() != null ? invocation.getThis().getClass() : null);/ If the transaction attribute is null, the method is non-transactional.final TransactionAttribute txAttr =getTransactionAttributeSource().getTransactionAttribute(invocation.getMethod(), targetClass);/拦截到方法的事务属性txAttr 如：PROPAGATION_REQUIRED,ISOLATION_DEFAULTfinal String joinpointIdentification = methodIdentification(invocation.getMethod();if (txAttr = null | !(getTransactionManager() instanceof CallbackPreferringPlatformTransactionManager) / Standard transaction demarcation with getTransaction and commit/rollback calls.TransactionInfo txInfo = createTransactionIfNecessary(txAttr, joinpointIdentification);/包括 （txAttr ，拦截到的方法joinPoint ，transaction Status ）调用底层Object transaction = doGetTransaction();开启事务。Object retVal = null;try / This is an around advice: Invoke the next interceptor in the chain./ This will normally result in a target object being invoked.retVal = ceed();catch (Throwable ex) / target invocation exceptioncompleteTransactionAfterThrowing(txInfo, ex);throw ex;finally cleanupTransactionInfo(txInfo);commitTransactionAfterReturning(txInfo); /调用父类TransactionAspectSupport(含transactionManager，transactionAttributeSource) /this.transactionMmit(txInfo.getTransactionStatus();return retVal;else / Its a CallbackPreferringPlatformTransactionManager: pass a TransactionCallback in.try Object result = (CallbackPreferringPlatformTransactionManager) getTransactionManager().execute(txAttr,new TransactionCallback() public Object doInTransaction(TransactionStatus status) TransactionInfo txInfo = prepareTransactionInfo(txAttr, joinpointIdentification, status);try return ceed();catch (Throwable ex) if (txAttr.rollbackOn(ex) / A RuntimeException: will lead to a rollback.throw new ThrowableHolderException(ex);else / A normal return value: will lead to a commit.return new ThrowableHolder(ex);finally cleanupTransactionInfo(txInfo););/ Check result: It might indicate a Throwable to rethrow.if (result instanceof ThrowableHolder) throw (ThrowableHolder) result).getThrowable();else return result;catch (ThrowableHolderException ex) throw ex.getThrowable();HibernateTransactionManager 真正实现事务的提交，回滚。（继承PlatformTransactionManager）protected void doCommit(DefaultTransactionStatus status) HibernateTransactionObject txObject = (HibernateTransactionObject) status.getTransaction();if (status.isDebug() logger.debug(Committing Hibernate transaction on Session +SessionFactoryUtils.toString(txObject.getSessionHolder().getSession() + );try txObject.getSessionHolder().getTransaction().commit();catch (org.hibernate.TransactionException ex) / assumably from commit call to the underlying JDBC connectionthrow new TransactionSystemException(Could not commit Hibernate transaction, ex);catch (HibernateException ex) / assumably failed to flush changes to databasethrow convertHibernateAccessException(ex);protected void doRollback(DefaultTransactionStatus status) HibernateTransactionObject txObject = (HibernateTransactionObject) status.getTransaction();if (status.isDebug() logger.debug(Rolling back Hibernate transaction on Session +SessionFactoryUtils.toString(txObject.getSessionHolder().getSession() + );try txObject.getSessionHolder().getTransaction().rollback();catch (org.hibernate.TransactionException ex) throw new TransactionSystemException(Could not roll back Hibernate transaction, ex);catch (HibernateException ex) / Shouldnt really happen, as a rollback doesnt cause a flush.throw convertHibernateAccessException(ex);finally if (!txObject.isNewSessionHolder() / Clear all pending inserts/updates/deletes in the Session./ Necessary for pre-bound Sessions, to avoid inconsistent state.txObject.getSessionHolder().getSession().cle