Datanucleus：从 @Transactional 转向非事务性
我正在使用 Datanucleus、JDO 和 Spring 与 Aspect-J 交织的声明式 @Transactional 管理。
但是，当“普通”方法从 @Transactional 方法获取持久对象时，该对象的状态将变为瞬态（持久管理器似乎已被删除）并且该对象不再是持久的。
示例：
public class Example {
public void test() throws Exception {
Login l = getLogin();
JDOHelper.getObjectState(l); // transient instead of persistent
l.getSomeOtherPersistentObj().doStuff(); // NullpointerException :(
}
@Transactional
private Login getLogin() {
// do transactional stuff here
// ..
return dao.find(Login.class, 1);
}
}
这是为什么？如何在不需要事务的地方添加 @Transactional 的情况下修复它？以下确实（显然）有效，因此这表明可以建立事务性连接和非事务性连接：
- @Transactional 方法调用 @Transactional 方法
- @Transactional 方法调用普通方法
- 普通方法调用普通方法
如果我调用 dao.refresh(l)，我得到：“ID 为“”的对象由不同的对象管理器管理”，所以 Spring 可能正在使用与 DAO 不同的持久性管理器，是这样吗？这 原因？
这是我的弹簧配置（可能相关）：
<bean id="pmf" class="org.datanucleus.api.jdo.JDOPersistenceManagerFactory" destroy-method="close">
<property name="connectionDriverName" value="com.mysql.jdbc.Driver"/>
...
<constructor-arg>
<map>
<entry key="datanucleus.autoCreateSchema" value="true" />
</map>
</constructor-arg>
</bean>
<bean id="myPmfProxy" class="org.springframework.orm.jdo.TransactionAwarePersistenceManagerFactoryProxy">
<property name="targetPersistenceManagerFactory" ref="pmf" />
</bean>
<bean id="transactionManager" class="org.springframework.orm.jdo.JdoTransactionManager">
<property name="persistenceManagerFactory" ref="myPmfProxy" />
</bean>
<bean id="JDODao" class="sw.JDODao">
<property name="persistenceManagerFactory" ref="myPmfProxy" />
</bean>
I am using Datanucleus, JDO and Spring's declarative @Transactional management woven with Aspect-J.
But when a 'normal' method gets a persistent object from a @Transactional method, the object's state will become transient (the persistence manager seems to be removed) and the object is no longer persistent.
Example:
public class Example {
public void test() throws Exception {
Login l = getLogin();
JDOHelper.getObjectState(l); // transient instead of persistent
l.getSomeOtherPersistentObj().doStuff(); // NullpointerException :(
}
@Transactional
private Login getLogin() {
// do transactional stuff here
// ..
return dao.find(Login.class, 1);
}
}
Why is this and how can I fix it without adding @Transactional in places where transactions are not needed? The following does (obviously) work so this indicates that a transactional as well as a non-transactional connection can be made:
- A @Transactional method calls a @Transactional method
- A @Transactional method calls a normal method
- A normal method calls a normal method
If I call dao.refresh(l), I get: 'Object with id "" is managed by a different Object Manager', so maybe Spring is working on a different persistence manager than the DAO, is this the cause?
Here's my spring configuration (it might be relevant):
<bean id="pmf" class="org.datanucleus.api.jdo.JDOPersistenceManagerFactory" destroy-method="close">
<property name="connectionDriverName" value="com.mysql.jdbc.Driver"/>
...
<constructor-arg>
<map>
<entry key="datanucleus.autoCreateSchema" value="true" />
</map>
</constructor-arg>
</bean>
<bean id="myPmfProxy" class="org.springframework.orm.jdo.TransactionAwarePersistenceManagerFactoryProxy">
<property name="targetPersistenceManagerFactory" ref="pmf" />
</bean>
<bean id="transactionManager" class="org.springframework.orm.jdo.JdoTransactionManager">
<property name="persistenceManagerFactory" ref="myPmfProxy" />
</bean>
<bean id="JDODao" class="sw.JDODao">
<property name="persistenceManagerFactory" ref="myPmfProxy" />
</bean>
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事实证明，我的对象需要可拆卸才能做到这一点。
我将
(detachable="true")添加到我的@PersistenceCapable注释中，并设置以下 datanucleus 选项：It turned out that my objects need to be detachable to do this.
Iv'e added
(detachable="true")to my@PersistenceCapableannotations and set the following datanucleus options: