当我按照这个教程http://zh-cn.netbeans.org/kb/docs/java/gui-db.html时出现下面的错误：
run:
2010-6-10 20:11:54 org.jdesktop.application.Application$1 run
严重: Application class carsapp.CarsApp failed to launch
javax.persistence.PersistenceException: No Persistence provider for EntityManager named car_databasePU: The following providers:
oracle.toplink.essentials.PersistenceProvider
oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider
Returned null to createEntityManagerFactory.
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:154)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at carsapp.CarsView.initComponents(CarsView.java:289)
at carsapp.CarsView.<init>(CarsView.java:36)
at carsapp.CarsApp.startup(CarsApp.java:19)
at org.jdesktop.application.Application$1.run(Application.java:171)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.Error: Application class carsapp.CarsApp failed to launch
at org.jdesktop.application.Application$1.run(Application.java:177)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Caused by: javax.persistence.PersistenceException: No Persistence provider for EntityManager named car_databasePU: The following providers:
oracle.toplink.essentials.PersistenceProvider
oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider
Returned null to createEntityManagerFactory.
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:154)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at carsapp.CarsView.initComponents(CarsView.java:289)
at carsapp.CarsView.<init>(CarsView.java:36)
at carsapp.CarsApp.startup(CarsApp.java:19)
at org.jdesktop.application.Application$1.run(Application.java:171)
... 8 more
成功生成（总时间：2 秒）
If so, then it is a known issue 119567 that is caused by a GlassFish
issue 3827. The workaround is to rename the directory to contain ASCII
letters only. See http://www.netbeans.org/issues/show_bug.cgi?id=119567
and https://glassfish.dev.java.net/issues/show_bug.cgi?id=3827 for more
details.