Hibernate - java.lang.NoClassDefFoundError

Question

使用Hiberate爲持久層實現Web服務。很好的工作，沒有錯誤。然而，當我寫一個單元測試獲得ServiceRegistry實例時訪問道一遇到這個錯誤：

ServiceRegistry sr = new ServiceRegistryBuilder().applySettings(
        configuration.getProperties()).buildServiceRegistry(); 

完整的堆棧跟蹤：

java.util.ServiceConfigurationError: org.hibernate.integrator.spi.Integrator: Provider org.jadira.usertype.dateandtime.joda.integrator.UserTypeJodaTimeHibernateIntegrator could not be instantiated: java.lang.NoClassDefFoundError: org/jadira/usertype/dateandtime/shared/spi/AbstractVersionableUserType 
    at java.util.ServiceLoader.fail(ServiceLoader.java:224) 
    at java.util.ServiceLoader.access$100(ServiceLoader.java:181) 
    at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:377) 
    at java.util.ServiceLoader$1.next(ServiceLoader.java:445) 
    at org.hibernate.service.classloading.internal.ClassLoaderServiceImpl.loadJavaServices(ClassLoaderServiceImpl.java:236) 
    at org.hibernate.integrator.internal.IntegratorServiceImpl.<init>(IntegratorServiceImpl.java:53) 
    at org.hibernate.service.internal.BootstrapServiceRegistryImpl.<init>(BootstrapServiceRegistryImpl.java:80) 
    at org.hibernate.service.internal.BootstrapServiceRegistryImpl.<init>(BootstrapServiceRegistryImpl.java:57) 
    at org.hibernate.service.ServiceRegistryBuilder.<init>(ServiceRegistryBuilder.java:76) 
    at com.dg.dao.SessionConfig.getSession(SessionConfig.java:26) 
    at com.dg.dao.CustomerHibernate.doGetSingleById(CustomerHibernate.java:210) 
    at com.dg.dao.CustomerHibernate.getCustomerByID(CustomerHibernate.java:44) 
    at com.dg.dao.test.CustomerDaoTest.testCustomerDao(CustomerDaoTest.java:27) 
    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:601) 
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) 
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) 
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) 
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestMethodCallbacks.evaluate(RunBeforeTestMethodCallbacks.java:74) 
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:82) 
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:72) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231) 
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) 
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) 
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) 
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) 
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) 
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) 
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) 
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) 
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309) 
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174) 
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) 
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390) 
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197) 
Caused by: java.lang.NoClassDefFoundError: org/jadira/usertype/dateandtime/shared/spi/AbstractVersionableUserType 

我已驗證類不存在於類路徑中。爲了糾正我需要得到舊版本的usertype.spi。

問題是，爲什麼它會嘗試在單元測試時使用舊的類文件，但在容器中運行服務時工作絕對正常？有沒有人看過這個問題？

Answer 1

我想通了，這個問題是由衝突以下依存關係中造成的：

<dependency> 
    <groupId>org.jadira.usertype</groupId> 
    <artifactId>usertype.jodatime</artifactId> 
    <version>2.0.1</version> 
</dependency> 

而且

<dependency> 
    <groupId>org.jadira.usertype</groupId> 
    <artifactId>usertype.core</artifactId> 
    <version>3.1.0.CR6</version> 
</dependency> 

問題涉及有關特別是因爲兩個軟件包包含PersistentDateTime類（雖然還有很多其他的重複類）。 PersistentDateTime的兩個實例都擴展了一個名爲AbstractVersionableUserType的類。唯一的是，這裏的基類都駐留在不同的包中。所以，當創建ServiceRegistry時，hibernate使用反射動態地加載這些類型。它爲junit炸彈的原因是hibernate試圖從usertype.jodatime包加載PersistentDateTime類，而需要加載的實際類來自usertype.core包。它只能在容器中工作，因爲使用了不同的類加載器。

無論如何，當刪除usertype.jodatime依賴項時，一切正常。