Spring Scheduler - 当存在循环依赖时,调度方法不会在事务中启动

Question

我正在使用一个使用Spring 3,Hibernate和JPA的应用程序.我有两个课程如下:

@Component
class Manager {
    @Autowired
    Util util;
}

和

@Component
class Util {
    @Autowired
    Manager manager;

    @Scheduled(fixedDelay = 1 * 60 * 1000)
    @Transactional(propagation = Propagation.REQUIRED)
    public void scheduledMethod(){
        // Need to update the database in a transaction
    }
}

申请背景的相关部分如下:

    <context:component-scan base-package="packageName" />
    <tx:annotation-driven />
    <bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
       <property name="persistenceUnitName" value="defaultPU" />
       <property name="dataSource" ref="dataSource" />
    </bean>
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
       <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>
    <task:annotation-driven executor="executor" scheduler="scheduler"/>
    <task:executor id="executor"
       pool-size="10"
       queue-capacity="10000"
       rejection-policy="CALLER_RUNS"/>
    <task:scheduler id="scheduler" pool-size="10"/>

使用此配置,我得到以下异常

javax.persistence.TransactionRequiredException: no transaction is in progress
        at org.hibernate.ejb.AbstractEntityManagerImpl.flush(AbstractEntityManagerImpl.java:978)
        at sun.reflect.GeneratedMethodAccessor88.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)
        at org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.invoke(ExtendedEntityManagerCreator.java:365)
        at com.sun.proxy.$Proxy43.flush(Unknown Source)
        at sun.reflect.GeneratedMethodAccessor88.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:601)
        at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
        at com.sun.proxy.$Proxy43.flush(Unknown Source)

如果我从Util类中删除Manager类的自动装配,它可以正常工作.此外,在调试时,我发现即使应用程序上下文文件中存在某些错误,预定方法也会开始执行.

由于某些遗留原因,我无法避免循环依赖.有人可以帮助解决为什么在循环依赖的情况下发生此异常？

Answer 1

您可以使用@PostConstruct 来实现此目的

@Component
class Manager {

    Util util;

    public void setUtil(Util util) {
        this.util =  util;
    }
}


@Component
class Util {
    @Autowired
    Manager manager;

    @PostConstruct
    public void init(){
        manager.setUtil(this);

    }

    @Scheduled(fixedDelay = 1 * 60 * 1000)
    @Transactional(propagation = Propagation.REQUIRED)
    public void scheduledMethod(){
        // Need to update the database in a transaction
    }
}