我正在尝试使用Eclipselink和MongoDB配置一个nosql持久性单元，但是我在部署期间遇到了以下堆栈异常;
...
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)
连接似乎已成功建立，但后来我得到一个java.lang.ClassCastException并且连接已关闭。
persistence.xml中的我的PU看起来像这样：
<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>
我的NoSQL实体类;
@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------------------------------------------------------------------
}
我正在使用CTM，所以我在无状态会话bean中调用PU;
@Stateless
public class TicketDAOImpl implements TicketDAO {
@PersistenceContext(unitName = "NoSQL_PU")
private EntityManager em;
}
我一直关注eclipselink guide，但我找不到与此相关的任何内容。
答案 0 :(得分：3)
问题在于我的持久性单元。默认情况下，包含所有实体类，因此我的NoSQL和SQL实体都被传递给SQL和NoSQL持久性单元。解决方案只是指定persistence.xml持久性单元中的实体。
<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>
答案 1 :(得分：0)
我使用EclipseLink 2.6.0获得了ClassCastException。 原来这是一个错误，它在2.6.1
中修复https://www.eclipse.org/eclipselink/downloads/milestones.php
错误：https://www.eclipse.org/forums/index.php/t/1068464/
注意：目前2.6.1尚未正式发布，但到目前为止它对我来说效果很好。
答案 2 :(得分：0)
我认为正确的答案应该在true字段中包含exclude-unlisted-classes。换句话说，它将排除不属于NoSQL JPA的实体类。因此，persistence.xml应该如下所示：
<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>