使用 DataNucleus 我在下面的第二个 INFO 语句中看到了一个问题（从底部开始的第二个条目）。
在使用 持久化对象后尝试读取或编辑对象时makePersistent()，我只得到空值，INFO 日志表明该对象不再由持久性管理器管理（尽管我在makePersistent()调用后立即执行这些编辑）。
我的猜测是与我的数据存储（本地嵌入/文件模式下的 NeoDatis）的连接正在关闭，因此持久性管理器停止管理它。但我只是使用 DataNucleusorg.datanucleus.jdo.JDOPersistenceManagerFactory类来创建连接。
知道为什么会发生这种情况吗？我是否认为关闭的连接消息是问题所在？
为简洁起见，删除了 FQDN 的缩短的和无关的日志：
DEBUG DataNucleus.Persistence - Making object persistent : "a.b.c.User@22a866a9"
INFO DataNucleus.Persistence - Managing Persistence of Class : a.b.c.User [Table : (none), InheritanceStrategy : new-table]
DEBUG DataNucleus.Connection - Connection added to the pool : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@28f337b, null] for key=o.dn.ExecutionContextImpl@59c12050 in factory=ConnectionFactory:tx[o.dn.s.neodatis.ConnectionFactoryImpl@3b626c6d]
DEBUG DataNucleus.Datastore - Opening NeoDatis ODB for "neodatis:file:database/neodatis_primary_datastore.odb" : org.neodatis.odb.impl.main.LocalODB@13a183d2
DEBUG DataNucleus.Datastore.Persist - Object "a.b.c.User@22a866a9" being inserted into NeoDatis with all reachable objects
DEBUG DataNucleus.Datastore.Persist - Object "a.b.c.User@22a866a9" (id="15) persisted to NeoDatis
DEBUG DataNucleus.Datastore - Committing NeoDatis ODB for "neodatis:file:database/neodatis_primary_datastore.odb" : org.neodatis.odb.impl.main.LocalODB@13a183d2
DEBUG DataNucleus.Connection - Connection removed from the pool : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@28f337b, null] for key=o.dn.ExecutionContextImpl@59c12050 in factory=ConnectionFactory:tx[o.dn.s.neodatis.ConnectionFactoryImpl@3b626c6d]
DEBUG DataNucleus.Connection - The connection has been closed : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@28f337b, null]
DEBUG DataNucleus.Reachability - Performing check of objects for "persistence-by-reachability" (commit) ...
DEBUG DataNucleus.Cache - Object "a.b.c.User@22a866a9" (id="15") added to Level 2 cache (loadedFlags="[YYYYYYY]", relationFields="null")
DEBUG DataNucleus.Transaction - Committing [DataNucleus Transaction, ID=Xid=, enlisted resources=[]]
DEBUG DataNucleus.Lifecycle - Object "a.b.c.User@22a866a9" (id="15") has a lifecycle change : "P_NEW"->"HOLLOW"
DEBUG DataNucleus.Transaction - Object "a.b.c.User@22a866a9" (id="15") being evicted from transactional cache
DEBUG DataNucleus.Transaction - Transaction committed in 7 ms
DEBUG DataNucleus.Lifecycle - Object "a.b.c.User@22a866a9" (id="15") has a lifecycle change : "HOLLOW"->"P_NONTRANS"
DEBUG DataNucleus.Persistence - Fetching object "a.b.c.User@22a866a9" (id=15) fields [authorities,createdFromIP,dateCreated,password,timeZoneID,username]
DEBUG DataNucleus.Datastore.Retrieve - Object "a.b.c.User@22a866a9" (id="15") being retrieved from NeoDatis
DEBUG DataNucleus.Connection - Connection added to the pool : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@39673d71, null] for key=o.dn.ExecutionContextImpl@59c12050 in factory=ConnectionFactory:tx[o.dn.s.neodatis.ConnectionFactoryImpl@3b626c6d]
DEBUG DataNucleus.Datastore - Opening NeoDatis ODB for "neodatis:file:database/neodatis_primary_datastore.odb" : org.neodatis.odb.impl.main.LocalODB@621f6c18
DEBUG DataNucleus.Datastore - Committing NeoDatis ODB for "neodatis:file:database/neodatis_primary_datastore.odb" : org.neodatis.odb.impl.main.LocalODB@621f6c18
DEBUG DataNucleus.Connection - Connection removed from the pool : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@39673d71, null] for key=o.dn.ExecutionContextImpl@59c12050 in factory=ConnectionFactory:tx[o.dn.s.neodatis.ConnectionFactoryImpl@3b626c6d]
DEBUG DataNucleus.Connection - The connection has been closed : [o.dn.s.neodatis.ConnectionFactoryImpl$ManagedConnectionImpl@39673d71, null]
INFO DataNucleus.Persistence - Request to populate fields of a.b.c.User@22a866a9 but this object is no longer managed by NeoDatis so replacing with a.b.c.User@7cf1cdfb
DEBUG DataNucleus.Datastore.Retrieve - Execution Time = 5 ms