问题
I'm trying to configure a nosql persistence unit using Eclipselink and MongoDB but Im getting the following stack exception during deployment;
...
SEVERE: java.lang.ClassCastException: org.eclipse.persistence.nosql.adapters.mongo.MongoPlatform cannot be cast to org.eclipse.persistence.internal.databaseaccess.DatabasePlatform
at org.eclipse.persistence.sequencing.TableSequence.onConnect(TableSequence.java:168)
at org.eclipse.persistence.sequencing.Sequence.onConnect(Sequence.java:270)
at org.eclipse.persistence.internal.sequencing.SequencingManager.onConnectSequences(SequencingManager.java:927)
at org.eclipse.persistence.internal.sequencing.SequencingManager.onConnectInternal(SequencingManager.java:747)
at org.eclipse.persistence.internal.sequencing.SequencingManager.onConnect(SequencingManager.java:700)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeSequencing(DatabaseSessionImpl.java:281)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:629)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:625)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.initializeDescriptors(DatabaseSessionImpl.java:565)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.postConnectDatasource(DatabaseSessionImpl.java:792)
at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.login(DatabaseSessionImpl.java:749)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:241)
at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:681)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:204)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.createEntityManagerImpl(EntityManagerFactoryDelegate.java:304)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:336)
at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:302)
at org.glassfish.persistence.jpa.JPADeployer$2.visitPUD(JPADeployer.java:451)
at org.glassfish.persistence.jpa.JPADeployer$PersistenceUnitDescriptorIterator.iteratePUDs(JPADeployer.java:510)
at org.glassfish.persistence.jpa.JPADeployer.iterateInitializedPUsAtApplicationPrepare(JPADeployer.java:492)
at org.glassfish.persistence.jpa.JPADeployer.event(JPADeployer.java:395)
at org.glassfish.kernel.event.EventsImpl.send(EventsImpl.java:131)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:484)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:527)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:523)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:356)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:522)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:546)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1423)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1500(CommandRunnerImpl.java:108)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1762)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1674)
at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534)
at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224)
at org.glassfish.grizzly.http.server.StaticHttpHandler.service(StaticHttpHandler.java:297)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:246)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:722)
The connection seems to be successfully established but then I get a java.lang.ClassCastException and the connection gets closed.
My PU in the persistence.xml looks like this:
<persistence-unit name="NoSQL_PU" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="eclipselink.target-database" value="org.eclipse.persistence.nosql.adapters.mongo.MongoPlatform"/>
<property name="eclipselink.nosql.connection-spec" value="org.eclipse.persistence.nosql.adapters.mongo.MongoConnectionSpec"/>
<property name="eclipselink.nosql.property.mongo.port" value="27017"/>
<property name="eclipselink.nosql.property.mongo.host" value="localhost"/>
<property name="eclipselink.nosql.property.mongo.db" value="dev"/>
<property name="eclipselink.logging.level" value="FINEST"/>
</properties>
</persistence-unit>
My NoSQL Entity class;
@NamedQueries({
@NamedQuery(name = "Comment.findAll", query = "SELECT e FROM Comment e"),
@NamedQuery(name = "Comment.findByPK", query = "SELECT e FROM Comment e WHERE e.id = :id"),})
@Entity
@NoSql(dataFormat = DataFormatType.MAPPED)
public class Comment implements Serializable {
// Serial-------------------------------------------------------------------
private static final long serialVersionUID = 1L;
// Variables----------------------------------------------------------------
@Id
@GeneratedValue
@Field(name="_id")
private String id;
@Basic
private Long created;
@Basic
private String commenterId;
@Basic
private String comment;
// Constructors-------------------------------------------------------------
// Getters------------------------------------------------------------------
// Setters------------------------------------------------------------------
}
Im using CTM so Im calling the PU in a stateless session bean;
@Stateless
public class TicketDAOImpl implements TicketDAO {
@PersistenceContext(unitName = "NoSQL_PU")
private EntityManager em;
}
Ive been following the eclipselink guide but I can't find anything pertaining to this.
回答1:
The problem was with my persistence unit. By default ALL the Entity classes are included, So both my NoSQL and SQL entities were being passed to both the SQL and the NoSQL persistence units. The solution was just to specify the entities inside the persistence.xml persistence unit.
<persistence-unit name="Dastrax_NoSQL_PU" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>declare_your_entity_1</class>
<class>declare_your_entity_2</class>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="eclipselink.target-database" value="org.eclipse.persistence.nosql.adapters.mongo.MongoPlatform"/>
<property name="eclipselink.nosql.connection-spec" value="org.eclipse.persistence.nosql.adapters.mongo.MongoConnectionSpec"/>
<property name="eclipselink.nosql.property.mongo.port" value="27017"/>
<property name="eclipselink.nosql.property.mongo.host" value="localhost"/>
<property name="eclipselink.nosql.property.mongo.db" value="dev"/>
<property name="eclipselink.logging.level" value="FINEST"/>
</properties>
</persistence-unit>
回答2:
I got the ClassCastException with EclipseLink 2.6.0. Turned out it was a bug and it is fixed in 2.6.1
https://www.eclipse.org/eclipselink/downloads/milestones.php
Bug: https://www.eclipse.org/forums/index.php/t/1068464/
Note: At this moment 2.6.1 is not officially released but it worked great for me so far.
回答3:
I think the correct answer would contain true in the exclude-unlisted-classes field. In other words, it would exclude the entity classes not belonging to the NoSQL JPA. Therefore, the persistence.xml should look as follows:
<persistence-unit name="Dastrax_NoSQL_PU" transaction-type="JTA">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>declare_your_entity_1</class>
<class>declare_your_entity_2</class>
<exclude-unlisted-classes>true</exclude-unlisted-classes>
<properties>
<property name="eclipselink.target-database" value="org.eclipse.persistence.nosql.adapters.mongo.MongoPlatform"/>
<property name="eclipselink.nosql.connection-spec" value="org.eclipse.persistence.nosql.adapters.mongo.MongoConnectionSpec"/>
<property name="eclipselink.nosql.property.mongo.port" value="27017"/>
<property name="eclipselink.nosql.property.mongo.host" value="localhost"/>
<property name="eclipselink.nosql.property.mongo.db" value="dev"/>
<property name="eclipselink.logging.level" value="FINEST"/>
</properties>
</persistence-unit>
来源：https://stackoverflow.com/questions/18119869/eclipselink-with-mongodb-java-lang-classcastexception