Question

当我尝试创建新的EntityManager以保留我的数据时，我收到以下错误：

javax.persistence.PersistenceException：无法构建实体管理器工厂

我使用的是Hibernate的JPA-Persistence Provider ......

不幸的是，我无法在stackoverflow / google搜索中找到任何有用的帖子......

是否有人知道错误的原因可能在哪里？

感谢您的帮助！

代码片段：

创建entitymanager

EntityManager em;
    EntityManagerFactory fact = Persistence.createEntityManagerFactory("bachelordebug"); // Here it crashes
    em = fact.createEntityManager();

栈跟踪

javax.persistence.PersistenceException: Unable to build entity manager factory
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:81)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
at com.uzh.platform.api.util.AssignmentUtil.findAll(AssignmentUtil.java:20)
at com.uzh.platform.api.services.GetAssignments.getAssignments(GetAssignments.java:22)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory$1.invoke(ResourceMethodInvocationHandlerFactory.java:81)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:151)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.invoke(AbstractJavaResourceMethodDispatcher.java:171)
at org.glassfish.jersey.server.model.internal.JavaResourceMethodDispatcherProvider$ResponseOutInvoker.doDispatch(JavaResourceMethodDispatcherProvider.java:152)
at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher.dispatch(AbstractJavaResourceMethodDispatcher.java:104)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:402)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:349)
at org.glassfish.jersey.server.model.ResourceMethodInvoker.apply(ResourceMethodInvoker.java:106)
at org.glassfish.jersey.server.ServerRuntime$1.run(ServerRuntime.java:259)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
at org.glassfish.jersey.internal.Errors.process(Errors.java:267)
at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:318)
at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:236)
at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1010)
at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:373)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:382)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:345)
at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:220)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
at com.thetransactioncompany.cors.CORSFilter.doFilter(CORSFilter.java:156)
at com.thetransactioncompany.cors.CORSFilter.doFilter(CORSFilter.java:233)
at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:766)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:114)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:326)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0"
         xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
                    http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd">
<persistence-unit name="bachelordebug" transaction-type="RESOURCE_LOCAL">
    <!-- <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider> -->
    <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
   <class>com.uzh.platform.data.dao.Assignment</class>
    <properties>
        <property name="javax.persistence.jdbc.driver" value="org.postgresql.Driver"/>
        <property name="javax.persistence.jdbc.url" value="jdbc:postgresql://127.0.0.1:5432/bachelor"/>
        <property name="javax.persistence.jdbc.user" value="bachelor"/>
        <property name="javax.persistence.jdbc.password" value="bachelor14"/>
        <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
        <property name="hibernate.hbm2ddl.auto" value="update"/>
        <property name="hibernate.connection.release_mode" value="after_statement"/>
        <property name="connection.pool_size" value="1"/>
        <property name="dialect" value="org.postgresql.Driver"/>
        <property name="current_session_context_class" value="thread"/>
        <property name="cache.provider_class" value="org.hibernate.cache.NoCacheProvider"/>
        <property name="show_sql" value="true"/>
    </properties>
</persistence-unit>

Answer 1

（在评论和编辑中回答了问题。请参阅Question with no answers, but issue solved in the comments (or extended in chat)）

OP写道：

解决

我终于找到了我的错误！

在我的JPA-Entity课程中，我拼错了我的Named-Query注释（即使我不使用它）

@NamedQuery(name="Assignment.findAll", query ="SELECT * FROM assignment")

当然，必须在大写字母中写一下，即“作业”（即它们出现在服务类中的所有术语！）
     这个愚蠢的错误浪费了3天 - 但现在我学会了如何做到这一点！： - ）

非常感谢您的帮助！

Answer 2

我遇到了同样的错误，不幸的是上面的回答对我没什么帮助。所以我查看了我发现此错误的其他错误：

com.mysql.cj.core.exceptions.InvalidConnectionAttributeException: The server time zone value 'EEST' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the serverTimezone configuration property) to use a more specifc time zone value if you want to utilize time zone support.

通过将我的连接网址替换为：＆＃34; jdbc：mysql：// localhost：3306 / db？useUnicode，我按照this回答及其注释解决了问题=真安培; useJDBCCompliantTimezoneShift =真安培; useLegacyDatetimeCode =假安培; serverTimezone = UTC ＆＃34;

解决了所有错误，包括这个问题中提到的错误：

javax.persistence.PersistenceException: Unable to build entity manager factory

我希望这有助于其他人遇到我面临的同样问题。

Answer 3

由于错误可能表明了很多不同的原因，因此最好找到原因检查Hibernate DEBUG日志语句（我们使用logback，但它应该在任何其他日志框架中同样工作）：

通过这个你可以得到很多输出，但是可以确定实际上有趣的类（你很可能已经在这里发现了原因）：

// (logback.groovy)

logger( "org.hibernate", DEBUG )

对我们来说，显示了以下内容（其中 Mapping collection: foo.Bar.field -> some_tab_x 是我们发现错误映射所需的信息）：

07:32:43.720 D~ [main ~ main] [     :     ] CollectionSecondPass:SecondPass:  67|  
  Second pass for collection: foo.Bar.field
07:32:43.720 D~ [main ~ main] [     :     ] c.a.CollectionBinder:SecondPass: 823|  
  Binding a OneToMany: foo.Bar.field through a foreign key
07:32:43.720 D~ [main ~ main] [     :     ] c.a.CollectionBinder:SecondPass: 861|  
  Mapping collection: foo.Bar.field -> some_tab_x
07:32:43.727 D~ [main ~ main] [     :     ] ePersistenceProvider:gerFactory:  82|  
  Unable to build entity manager factory
07:32:43.743 E~ [main ~ main] [     :     ] .l.f.m.m.MgFooTstJu:AndRethrow:  74|  
  MyException: unit test error loading Foo with id: 4342153208-2: 
  <java.lang.NullPointerException> => 
  <javax.persistence.PersistenceException: Unable to build entity manager factory>

要再次限制日志记录（如果有多个地方可以修复JPA映射），我们会使用以下内容：

// (logback.groovy)

//logger( "org.hibernate", DEBUG )  // log everything

// infos on annotation mappping, e.g. getting NullPointerExceptions with 
//   javax.persistence.PersistenceException: Unable to build entity manager factory
logger( "org.hibernate.cfg.annotations.CollectionBinder", DEBUG )

（例如，如果日志输出没有显示完整的类名，那么只需使用CTRL+SHIFT+T来搜索您想要调试的类型）

Answer 4

在您的实体类中添加id注释

@Entity
public class yourClass{
  @Id
  private Long id;
  ...
 }

javax.persistence.PersistenceException：无法构建实体管理器工厂

4 个答案: