Java 如何从其他jar加载持久性单元？

谢谢大家

我有三个JAR，一个是dao逻辑，另一个是持久性归档（映射、persistence.xml和一些orm文件），另一个是应用程序项目。 我正在使用intellij idea 13和gradle开发此应用程序，但在应用程序项目中，当我尝试运行时，会出现下一个错误：

Exception [EclipseLink-30009] (Eclipse Persistence Services - 2.5.1.v20130918-f2b9fc5): org.eclipse.persistence.exceptions.PersistenceUnitLoadingException
Exception Description: An exception was thrown while trying to load persistence unit at url: file:/F:/IdeaProjects/com.reyma.db/out/artifacts/com_reyma_db/com.reyma.db.jar
Internal Exception: java.lang.NullPointerException
    at org.eclipse.persistence.exceptions.PersistenceUnitLoadingException.exceptionLoadingFromUrl(PersistenceUnitLoadingException.java:100)
    at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processPersistenceArchive(PersistenceUnitProcessor.java:597)
    at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.getPersistenceUnits(PersistenceUnitProcessor.java:481)
    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:177)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79)
    at javax.persistence.Persistence$createEntityManagerFactory.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)
    at com.srs.jpa.EntityManagerProviderImpl.initializeEntityManager(EntityManagerProviderImpl.groovy:59)
    at com.srs.jpa.interfaces.IEntityManagerProvider$initializeEntityManager.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)
    at com.reyma.main.InitializeEntityManager.initialize(InitializeEntityManager.groovy:43)
    at com.reyma.main.InitializeEntityManager$initialize.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112)
    at com.reyma.main.Main.start(Main.groovy:62)
    at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
    at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
    at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
    at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
    at org.eclipse.persistence.internal.jpa.deployment.xml.parser.PersistenceContentHandler.endElement(PersistenceContentHandler.java:143)

---

我想问题是我的dao和持久性部分是分开的，但是，我如何解决这个问题？

你有堆栈跟踪吗？我添加了完整的错误，希望你能帮助我。。。