Transaction and save point
Transaction: Transaction, generally refers to something to be done or done. In computer terms, it refers to a program execution unit (unit) that accesses and may update various data items in the database.
A group of operations are either executed at the same time or not executed at the same time, such as transferring money.
Setting of transaction savepoint
Connection conn=null;
Savepoint savepoint =null;//保存点
try{
//1.获得链接
conn=~~~~;
//2.开启事务
conn.setAutoCommit(false);
A,B
savepoint = conn.setSavepoint();
C,D
//3.事务提交
conn.commit();
}catch(e){
if(savepoint != null){
conn.rollback(savepoint);//C,D异常
conn.commit();//提交AB
}else{
conn.rollback();}
}
Spring transaction management interface
Transaction management interface {T ransaction D efinition (transaction definition, attributes, details) T ransaction Starus (transaction status) P latform T ransaction Manage (platform transaction manager) \mathrm{transaction management interface}\left\ {\begin{array}{l}TransactionDefinition(transaction definition, attributes, details)\\TransactionStatus(transaction status)\\PlatformTransactionManage(platform transaction manager)\end{array}\right. Business affairs tube management of the access port⎩⎨⎧T R & lt A n- S A C T I O n- D E F I n- I T I O n- ( what service is given sense , the genus properties , details of the situation )T R & lt A n- S A C T I O n- S T A T U S ( what service is like state )P L A T F O R & lt m T R & lt A n- S A C T I O n- M A n- A G E ( level station things traffic pipe management device )
事 务 管 理 的 j a r 包 ( W E N − I N F / l i b ) { s p r i n g − t x − 3.2.0. R E L E S A 3 E . j a r P l a t f o r m T r a n s a c t i o n M a n a g e { s p r i n g − j d b c − 3.2.0. R E L E A S E . j a r s p r i n g − o r m − 3.2.0. R E L E A S E . j a r \begin{array}{c}\mathrm{事务管理的}jar包\\(WEN-INF/lib)\end{array}\left\{\begin{array}{l}spring-tx-3.2.0.RELESA3E.jar\\PlatformTransactionManage\left\{\begin{array}{l}spring-jdbc-3.2.0.RELEASE.jar\\spring-orm-3.2.0.RELEASE.jar\end{array}\right.\end{array}\right. What service pipe management of J A R & lt packet( W E N−I N F / l i b )⎩⎨⎧spring−tx−3.2.0.RELESA3E.jarPlatformTransactionManage{
spring−jdbc−3.2.0.RELEASE.jarspring−o r m−3.2.0.RELEASE.jar
| The methods of TransactionDefinition transaction details are: | description |
|---|---|
| ①getPropagarionBehavior():int | Communication behavior (how to share affairs between two businesses) |
| ②getIsolationLevel():int | Isolation level |
| ③getTimeout():int | Get timeout |
| ④isReadOnly:boolean | Read-only |
| ⑤getName():String | Configure the transaction details name (general method names such as add, save, etc.) |
| ①There are 7 parameters for getPropagarionBehavior propagation behavior (how to share transactions between two businesses), the more important ones are * | Explanation |
|---|---|
| TransactionDefinition.PROPAGATION_REQUIRED* | If there is a transaction currently, Spring will use that transaction; otherwise, a new transaction will be started |
| TransactionDefinition.PROPAGATION_SUPPORTS | If there is a transaction currently, Spring will use that transaction; otherwise, a new transaction will not be started |
| TransactionDefinition.PROPAGATION_MANDATORY | If there is a transaction currently, Spring will use that transaction; otherwise, an exception will be thrown |
| TransactionDefinition.PROPAGATION_REQUIRES_NEW* | Spring always starts a new transaction. If there is a transaction, the transaction is suspended |
| TransactionDefinition.PROPAGATION_NOT_SUPPORTED | Spring will not execute the code in the transaction. The code is always executed in a non-transactional environment, if there is a current transaction, the transaction is suspended |
| TransactionDefinition. PROPAGATION_NEVER | Even if there is a transaction currently, Spring will execute in a non-transactional environment. If there is currently a transaction, throw an exception |
| TransactionDefinition. PROPAGATION_NESTED | If there is a transaction currently, it is executed in a nested transaction. If not, start a new transaction. The bottom layer of transaction A and B uses a savepoint mechanism to form a nested transaction |