我的 RCP 应用程序中有以下代码：
EntityManagerFactory emf = Persistence.createEntityManagerFactory("todos");
EntityManager em = emf.createEntityManager();
Query q = em.createQuery("select t from Todo t");
@SuppressWarnings("unchecked")
List<Todo> todos = (List<Todo>)q.getResultList();
我的配置是 META-INF/persistence.xml 并包含：
<?xml version="1.0" encoding="UTF-8" ?>
<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_2_0.xsd"
version="2.0" xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="todos" transaction-type="RESOURCE_LOCAL">
<class>foo.bar.Todo</class>
<properties>
<property name="javax.persistence.jdbc.driver"
value="org.apache.derby.jdbc.EmbeddedDriver" />
<property name="javax.persistence.jdbc.url"
value="jdbc:derby:/home/pocon64/myDb;create=true" />
<property name="javax.persistence.jdbc.user" value="test" />
<property name="javax.persistence.jdbc.password" value="test" />
<!-- EclipseLink should create the database schema automatically -->
<property name="eclipselink.ddl-generation" value="create-tables" />
<property name="eclipselink.ddl-generation.output-mode"
value="database" />
</properties>
</persistence-unit>
</persistence>
当我尝试运行该应用程序时，它启动正常，但显示错误：
Could not create the view:
Exception Description: An exception was thrown while searching for persistence archives with ClassLoader: org.eclipse.core.runtime.internal.adaptor.ContextFinder@4b51ac10
Internal Exception: Exception [EclipseLink-30009] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while trying to load persistence unit at url: bundleresource://51.fwk2013125681:10
Internal Exception: Exception [EclipseLink-30004] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while processing persistence.xml from URL: bundleresource://51.fwk2013125681:10
Internal Exception:
(1. URI was not reported to parser for entity [document])
根本没有创建 db 文件。任何想法是什么原因造成的？
添加：下面的完整堆栈跟踪：
Local Exception Stack:
Exception [EclipseLink-30009] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while trying to load persistence unit at url: bundleresource://51.fwk998462082:10
Internal Exception: Exception [EclipseLink-30004] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while processing persistence.xml from URL: bundleresource://51.fwk998462082:10
Internal Exception:
(1. URI was not reported to parser for entity [document])
at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionLoadingFromUrl(PersistenceUnitLoadingException.java:100)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processPersistenceArchive(PersistenceUnitProcessor.java:538)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.getPersistenceUnits(PersistenceUnitProcessor.java:444)
at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.findPersistenceUnitInfoInArchive(JPAInitializer.java:172)
at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.findPersistenceUnitInfoInArchives(JPAInitializer.java:154)
at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.findPersistenceUnitInfo(JPAInitializer.java:135)
at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:73)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)
at com.diligentgaming.dcm.workstation.plugins.core.dashboard.DashboardView.createPartControl(DashboardView.java:64)
at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:375)
at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:229)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
at org.eclipse.ui.internal.ViewPane.setVisible(ViewPane.java:534)
at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1245)
at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1198)
at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1597)
at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:643)
at org.eclipse.ui.internal.PartStack.createControl(PartStack.java:570)
at org.eclipse.ui.internal.PartSashContainer.createControl(PartSashContainer.java:568)
at org.eclipse.ui.internal.PerspectiveHelper.activate(PerspectiveHelper.java:272)
at org.eclipse.ui.internal.Perspective.onActivate(Perspective.java:981)
at org.eclipse.ui.internal.WorkbenchPage.onActivate(WorkbenchPage.java:2714)
at org.eclipse.ui.internal.WorkbenchWindow$28.run(WorkbenchWindow.java:3030)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchWindow.setActivePage(WorkbenchWindow.java:3011)
at org.eclipse.ui.internal.WorkbenchWindow.busyOpenPage(WorkbenchWindow.java:799)
at org.eclipse.ui.internal.Workbench$23.runWithException(Workbench.java:1229)
at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3938)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3615)
at org.eclipse.ui.application.WorkbenchAdvisor.openWindows(WorkbenchAdvisor.java:803)
at org.eclipse.ui.internal.Workbench$33.runWithException(Workbench.java:1600)
at org.eclipse.ui.internal.StartupThreading$StartupRunnable.run(StartupThreading.java:31)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3938)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3615)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2609)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at com.diligentgaming.dcm.workstation.plugins.core.Application.start(Application.java:20)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
Caused by: Exception [EclipseLink-30004] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while processing persistence.xml from URL: bundleresource://51.fwk998462082:10
Internal Exception:
(1. URI was not reported to parser for entity [document])
at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionProcessingPersistenceXML(PersistenceUnitLoadingException.java:118)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processPersistenceXML(PersistenceUnitProcessor.java:587)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processPersistenceArchive(PersistenceUnitProcessor.java:536)
... 63 more
Caused by:
(1. URI was not reported to parser for entity [document])
at org.eclipse.persistence.internal.jpa.deployment.xml.parser.XMLExceptionHandler.error(XMLExceptionHandler.java:28)
at org.eclipse.persistence.internal.jpa.deployment.xml.parser.XMLExceptionHandler.warning(XMLExceptionHandler.java:23)
at gnu.xml.aelfred2.SAXDriver.warn(SAXDriver.java:935)
at gnu.xml.aelfred2.SAXDriver.startExternalEntity(SAXDriver.java:631)
at gnu.xml.aelfred2.XmlParser.pushURL(XmlParser.java:3358)
at gnu.xml.aelfred2.XmlParser.doParse(XmlParser.java:159)
at gnu.xml.aelfred2.SAXDriver.parse(SAXDriver.java:320)
at gnu.xml.aelfred2.XmlReader.parse(XmlReader.java:294)
at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processPersistenceXML(PersistenceUnitProcessor.java:577)
... 64 more</code>