Spring @Transactional只讀

Question

我有一個基本的SpringBoot應用程序。 使用Spring Initializer，嵌入式Tomcat，Thymeleaf模板引擎以及作為可執行JAR文件的軟件包

有了這種依賴

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

我創建了聲明為readOnly的服務：

@Service
@Transactional(readOnly = true)
public class TimeLapseService {

    @Autowired
    TimeLapseRepository timeLapseRepository;

    public Set<TimeLapse> findAllByCompanyId(long companyId) {
        return timeLapseRepository.findAllByCompanyId(companyId);
    }

    public Iterable<TimeLapse> findAll (User user) {

        if (user.isAdmin()) {
            return timeLapseRepository.findAll();
        } else {
            return timeLapseRepository.findAllByCompanyId(user.getCompany().getId());
        }   

    }

    public void createTimeLapse (TimeLapse timeLapse) {
        timeLapseRepository.save (timeLapse);
    }

}

和

public interface TimeLapseRepository extends CrudRepository<TimeLapse, Long> {
....
}

據我所知，由於服務被聲明為只讀，因此創建新服務不應將任何內容持久化到數據庫，但會在TABLE中創建一行

timeLapseService.createTimeLapse(timeLapse24h);

JPA屬性：

spring.datasource.url=jdbc:h2:mem:testdb;MODE=MySQL;DB_CLOSE_ON_EXIT=FALSE
spring.datasource.username=sa
spring.datasource.password=
spring.jpa.show-sql=true
spring.jpa.properties.hibernate.format_sql=true
hibernate.dialect=org.hibernate.dialect.H2Dialect

Answer 1

BeanS調用一個transactional = read-only Bean1，它執行查找並調用transactional = read-write Bean2，該Bean2保存一個新對象。

> Bean1 starts a read-only tx. 31 09:39:44.199 [pool-1-thread-1] DEBUG
> o.s.orm.jpa.JpaTransactionManager - Creating new transaction with name
> [nz.co.vodafone.wcim.business.Bean1.startSomething]:
> PROPAGATION_REQUIRED,ISOLATION_DEFAULT,readOnly; ''

> 
> Bean 2 pariticipates in it. 31 09:39:44.230 [pool-1-thread-1] DEBUG
> o.s.orm.jpa.JpaTransactionManager - Participating in existing
> transaction
> 

什么都沒有提交給數據庫。

現在更改Bean2 @Transactional批注以添加propagation = Propagation.REQUIRES_NEW

> Bean1 starts a read-only tx. 31 09:31:36.418 [pool-1-thread-1] DEBUG
> o.s.orm.jpa.JpaTransactionManager - Creating new transaction with name
> [nz.co.vodafone.wcim.business.Bean1.startSomething]:
> PROPAGATION_REQUIRED,ISOLATION_DEFAULT,readOnly; ''
> 
> Bean2 starts a new read-write tx 31 09:31:36.449 [pool-1-thread-1]
> DEBUG o.s.orm.jpa.JpaTransactionManager - Suspending current
> transaction, creating new transaction with name

除非您進行如下操作，否則它將一直存在

    @Transactional(readOnly = false, propagation = Propagation.REQUIRES_NEW)
    public void createTimeLapse (TimeLapse timeLapse)
   { 
    timeLapseRepository.save (timeLapse); 
   }