Operate database transactions with jpatractionmanager

Transactions in a narrow sense refer to database transactions . It is mainly when multiple applications access the database concurrently , Transactions provide a means of isolation between these applications , To prevent the operation of each other from interfering with each other
Transactions provide a way for database operation sequence to recover from failure to normal state , At the same time, it provides a method to keep data consistency even in abnormal state .
A transaction has four characteristics , atomicity （Atomicity )、 Uniformity （Consistency )、 Isolation, （Isolation) And persistence （Durability), Referred to as transaction ACID characteristic .
use JpaTransactionManager Code to manipulate database transactions ：

  JpaTransactionManager transactionManager = applicationContext.getBean(JpaTransactionManager.class);
        DefaultTransactionDefinition def = new DefaultTransactionDefinition();
        def.setPropagationBehavior(TransactionDefinition.PROPAGATION_REQUIRES_NEW); //  Isolation level of things , Start a new business , It'll be safer .
        TransactionStatus status = transactionManager.getTransaction(def); //  Get transaction state 
        Project project;
        try {
    
         ...( Own business logic )
            transactionManager.commit(status);
        } catch (Exception e) {
    
            transactionManager.rollback(status);
            log.error("addProject error:{}", ExceptionUtils.getStackTrace(e));
            throw new BusinessException(" Failed to create project group ");
        }

        publisher.publishEvent(new CreateProjectEvent().setProject(project));
    }