Java GAE+；弹簧&x2B；JDO-PersistenceManagerFactory初始化错误

我有一个标准的PMF等级：

public class PMF {

    private static final PersistenceManagerFactory persistenceManagerFactory = JDOHelper
        .getPersistenceManagerFactory("transactions-optional");

    private PMF() {
    }

    public static PersistenceManagerFactory get() {
        return persistenceManagerFactory;
    }

}

在本地appengine服务器上运行， 第一次调用PMF.get（）时，出现以下异常：

javax.jdo.JDOFatalInternalException: Unexpected exception caught.
    at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(JDOHelper.java:1193)
    at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:808)
    at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:1093)
    at javax.jdo.JDOHelper.getPersistenceManagerFactory(JDOHelper.java:919)
    at com.myapp.framework.PMF.<clinit>(PMF.java:17)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
    at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
    ...
NestedThrowablesStackTrace:
java.lang.reflect.InvocationTargetException
    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 com.google.appengine.tools.development.agent.runtime.Runtime.invoke(Runtime.java:115)
    at javax.jdo.JDOHelper$16.run(JDOHelper.java:1965)
    at java.security.AccessController.doPrivileged(Native Method)
    at javax.jdo.JDOHelper.invoke(JDOHelper.java:1960)
    at javax.jdo.JDOHelper.invokeGetPersistenceManagerFactoryOnImplementation(JDOHelper.java:1166)
    ...
Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.apache.log4j.LogManager
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:169)
    at com.google.appengine.tools.development.agent.runtime.RuntimeHelper.checkRestricted(RuntimeHelper.java:70)
    at com.google.appengine.tools.development.agent.runtime.Runtime.checkRestricted(Runtime.java:64)
    at org.apache.log4j.Logger.getLogger(Logger.java:104)
    at org.datanucleus.util.Log4JLogger.<init>(Log4JLogger.java:49)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance_(Runtime.java:127)
    at com.google.appengine.tools.development.agent.runtime.Runtime.newInstance(Runtime.java:135)
    at org.datanucleus.util.NucleusLogger.getLoggerInstance(NucleusLogger.java:140)
    at org.datanucleus.util.NucleusLogger.<clinit>(NucleusLogger.java:106)
    at org.datanucleus.plugin.PluginRegistryFactory.newInstance(PluginRegistryFactory.java:104)
    at org.datanucleus.plugin.PluginRegistryFactory.newPluginRegistry(PluginRegistryFactory.java:63)
    at org.datanucleus.plugin.PluginManager.<init>(PluginManager.java:61)
    at org.datanucleus.plugin.PluginManager.createPluginManager(PluginManager.java:427)
    at org.datanucleus.NucleusContext.<init>(NucleusContext.java:224)
    at org.datanucleus.NucleusContext.<init>(NucleusContext.java:204)
    at org.datanucleus.NucleusContext.<init>(NucleusContext.java:182)
    at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.<init>(JDOPersistenceManagerFactory.java:409)
    at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.createPersistenceManagerFactory(JDOPersistenceManagerFactory.java:294)
    at org.datanucleus.api.jdo.JDOPersistenceManagerFactory.getPersistenceManagerFactory(JDOPersistenceManagerFactory.java:195)
    ... 82 more

“我的库”文件夹中包含的库包括： -sdk中包含的所有GAE库都使用EclipseGoogle插件 -Spring MVC、Jackson和Aspectj包括使用常春藤和常春藤eclipse插件：

<dependencies>
    <dependency org="org.springframework" name="spring-webmvc" rev="3.2.0.RELEASE" />
    <dependency org="org.codehaus.jackson" name="jackson-mapper-asl" rev="1.9.11" />
    <dependency org="org.aspectj" name="aspectjrt" rev="1.7.1" />
    <dependency org="org.aspectj" name="aspectjweaver" rev="1.7.1" />
</dependencies>

---

我真的不明白为什么它会失败，因为通常log4j是由GAE支持的。

我从spring依赖项中排除了log4j，我不再得到错误。 在我的常春藤档案中：

<dependency org="org.springframework" name="spring-webmvc" rev="3.2.0.RELEASE">
    <exclude org="log4j" module="log4j" />
</dependency>

看起来您没有将Log4j jar添加到项目中，或者这个jar没有上传到GAE服务器。事实上，我的lib文件夹中有一个来自spring dependencies的Log4j-1.2.14.jar，它很好地复制到了GAE服务器，但GAE似乎阻止了类加载。当我从spring依赖项中排除log4j时，我不再得到错误。使用此解决方案，我可以松一些日志吗？

<dependency org="org.springframework" name="spring-webmvc" rev="3.2.0.RELEASE">
    <exclude org="log4j" module="log4j" />
</dependency>