Spring --- declarative transaction

1, the Spring's transaction mechanism

　　　　1.1, all data access technology has transaction processing, these technologies provide an API to  open the transaction , the transaction is committed   to complete operational data ( abnormal transaction rollback );

　　　　1.2, the Spring's transaction mechanism   : a unified mechanism   to handle  transaction processing different data access technologies ;

　　　　1.3, the Spring's transaction mechanism   provides a    PlatformTransactionManager interface to different data access technology    to use  a different interface :

　　　　　　　　　　

 

2, the Spring's declarative transaction

　　　　2.1, Spring declarative transaction support, namely  the use of annotations @Transactional in the way   that this method requires transaction support;

　　　　　　　　　　Annotated method when invoked , Spring open a new transaction , when no abnormal operation after the end of the method , the Spring will be submitted to the transaction ;

　　　　　　　　　　The annotation @Transactional located at org.springframework.transaction.annotation packet ;

　　@Transactional
    public void test(){

    }

　　　　2.2, Spring provides   @EnableTransactionManagement   on the configuration class  open declarative transaction support ;

　　　　　　　　　　After using @EnableTransactionManagement , the Spring container    will be    automatically annotated @Transactional scanning method, the class ;

3, notes transactional behavior

　　　　@Transactional   defines propagation , Isolation , timeout , readOnly , rollbackFor , noRollbackFor to customize transactional behavior :

　　　　　　　　

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4, the class level using @Transactional

　　　　4.1、@Transactional  不仅  可以用在方法上 ，还  可以使用在类上；

　　　　4.2、@Transactional   注解在类上时，整个类的所有public方法都是开启事务的；

　　　　　　　　如果   类级别、方法级别  同时使用@Transactional，类级别  会  重载方法级别；