时间戳

首页 > 解决方案 > 休眠无法加载类[]

java - 休眠无法加载类[]

问题描述

我最近使用 JPA（使用休眠）添加了一些功能（将数据库表连接到其他表）。它以前工作得很好，但现在我得到了例外org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class []——或者至少我认为这是其中最相关的部分。整个例外是：

org.apache.tapestry5.ioc.internal.OperationException: 
org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.apache.tapestry5.ioc.internal.OperationTrackerImpl.logAndRethrow(OperationTrackerImpl.java:186)
    at org.apache.tapestry5.ioc.internal.OperationTrackerImpl.run(OperationTrackerImpl.java:62)
    at org.apache.tapestry5.ioc.internal.PerThreadOperationTracker.run(PerThreadOperationTracker.java:60)
    at org.apache.tapestry5.ioc.internal.RegistryImpl.run(RegistryImpl.java:1254)
    at org.apache.tapestry5.ioc.internal.StartupDefImpl.invoke(StartupDefImpl.java:48)
    at org.apache.tapestry5.ioc.internal.RegistryImpl$2.run(RegistryImpl.java:230)
    at org.apache.tapestry5.ioc.internal.RegistryImpl.performRegistryStartup(RegistryImpl.java:361)
    at org.apache.tapestry5.ioc.internal.RegistryWrapper.performRegistryStartup(RegistryWrapper.java:89)
    at org.apache.tapestry5.TapestryFilter.init(TapestryFilter.java:110)
    at org.eclipse.jetty.servlet.FilterHolder.initialize(FilterHolder.java:138)
    at org.eclipse.jetty.servlet.ServletHandler.initialize(ServletHandler.java:852)
    at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:298)
    at org.eclipse.jetty.webapp.WebAppContext.startWebapp(WebAppContext.java:1349)
    at org.eclipse.jetty.maven.plugin.JettyWebAppContext.startWebapp(JettyWebAppContext.java:297)
    at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1342)
    at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:741)
    at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:505)
    at org.eclipse.jetty.maven.plugin.JettyWebAppContext.doStart(JettyWebAppContext.java:366)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
    at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:163)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:132)
    at org.eclipse.jetty.server.Server.start(Server.java:387)
    at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:114)
    at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:61)
    at org.eclipse.jetty.server.Server.doStart(Server.java:354)
    at org.eclipse.jetty.maven.plugin.JettyServer.doStart(JettyServer.java:73)
    at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:68)
    at org.eclipse.jetty.maven.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:535)
    at org.eclipse.jetty.maven.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:358)
    at org.eclipse.jetty.maven.plugin.JettyRunMojo.execute(JettyRunMojo.java:167)
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
    at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
    at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
    at org.codehaus.classworlds.Launcher.main(Launcher.java:47)
Caused by: java.lang.RuntimeException: org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.apache.tapestry5.ioc.internal.StartupDefImpl$1.run(StartupDefImpl.java:84)
    at org.apache.tapestry5.ioc.internal.OperationTrackerImpl.run(OperationTrackerImpl.java:56)
    ... 59 more
Caused by: org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:244)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:208)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
    at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:217)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
    at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:770)
    at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:797)
    at org.hibernate.jpa.HibernatePersistenceProvider.createContainerEntityManagerFactory(HibernatePersistenceProvider.java:135)
    at org.apache.tapestry5.internal.jpa.EntityManagerSourceImpl.createEntityManagerFactory(EntityManagerSourceImpl.java:224)
    at org.apache.tapestry5.internal.jpa.EntityManagerSourceImpl.getEntityManagerFactory(EntityManagerSourceImpl.java:200)
    at org.apache.tapestry5.internal.jpa.EntityManagerSourceImpl.create(EntityManagerSourceImpl.java:293)
    at $EntityManagerSource_b8af25bcbdf4.create(Unknown Source)
    at org.apache.tapestry5.internal.jpa.EntityManagerManagerImpl.getOrCreateEntityManager(EntityManagerManagerImpl.java:80)
    at org.apache.tapestry5.internal.jpa.EntityManagerManagerImpl.createAllEntityManagers(EntityManagerManagerImpl.java:70)
    at org.apache.tapestry5.internal.jpa.EntityManagerManagerImpl.getEntityManagers(EntityManagerManagerImpl.java:61)
    at $EntityManagerManager_b8af25bcbdf3.getEntityManagers(Unknown Source)
    at $EntityManagerManager_b8af25bcbdf2.getEntityManagers(Unknown Source)
    at org.apache.tapestry5.jpa.modules.JpaModule.startupEarly(JpaModule.java:187)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.apache.tapestry5.ioc.internal.StartupDefImpl$1.run(StartupDefImpl.java:70)
    ... 60 more
Caused by: org.hibernate.boot.registry.classloading.spi.ClassLoadingException: Unable to load class []
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:229)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.loadDriverIfPossible(DriverManagerConnectionProviderImpl.java:183)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildCreator(DriverManagerConnectionProviderImpl.java:139)
    at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:78)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:217)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:189)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
    at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
    at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
    at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:234)
    ... 86 more
Caused by: java.lang.ClassNotFoundException: 
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:348)
    at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.classForName(ClassLoaderServiceImpl.java:226)
    ... 97 more

您可能会意识到，我也在使用挂毯，但我想这无关紧要。

值得注意的是，我连接的表之前已经存在（没有连接），因此已经在persistence.xml.

我在代码中找不到导致此异常的部分，并且该消息Unable to load class []对我没有多大帮助。进入反编译的类也没有帮助，所以我在这里没有想法了。

因为我没有找到任何关于这个带有空类名的错误消息（与这样的帖子相反），也许你可以帮助我。

如果您需要任何源代码，我可以为您编写一些代码，与原始代码相似，但我无法提供原始代码本身。但是因为我主要想解释这个异常消息，所以这应该不是问题。

编辑这变得更奇怪了：我将本地版本恢复到 git 存储库的最后工作状态，但错误仍然存​​在。我猜这一定与Maven有关。

标签： javahibernatejpatapestry

解决方案

好吧，这太愚蠢了。

我只是忘了构建整个项目——我一直使用 IntelliJs 内置的构建功能，它在大多数情况下都有效——但显然不是所有时候。无论如何，如果您遇到同样的问题，请尝试在此之前构建您的项目。

推荐阅读