引起者：java.lang.NoClassDefFoundError：org / apache / log4j / Logger [英] Caused By: java.lang.NoClassDefFoundError: org/apache/log4j/Logger
问题描述
我遇到了一个有趣的问题，在运行时没有找到org.apache.log4j.Logger类。我正在尝试获得授权，这就是它失败的地方：
I've got an interesting problem in which the org.apache.log4j.Logger class is not found during runtime. I'm trying to get authorized and that is where it's failing:
OAuthAuthorizer oauthAuthorizer = new OAuthAuthorizer（OAUTH_CONSUMER_KEY，OAUTH_CONSUMER_SECRET，SAML_PROVIDER_ID，userId）;
我正在使用JDeveloper 11.1.1.6。以下是我所知道的：
I'm using JDeveloper 11.1.1.6. Here is what I know:
-
我查看了我的UI.war / WEB-INF / lib目录，我看到了那里有log4j-1.2.17.jar。
I've looked in my UI.war/WEB-INF/lib directory and I see the log4j-1.2.17.jar there.
抱怨它的类是org.opensaml.xml.XMLConfigurator
The class complaining about it is org.opensaml.xml.XMLConfigurator
Caused by: java.lang.NoClassDefFoundError: org/apache/log4j/Logger
at org.opensaml.xml.XMLConfigurator.<clinit>(XMLConfigurator.java:60)
at org.opensaml.DefaultBootstrap.initializeXMLTooling(DefaultBootstrap.java:195)
at org.opensaml.DefaultBootstrap.bootstrap(DefaultBootstrap.java:91)
at com.intuit.ipp.aggcat.util.SAML2AssertionGenerator.getSAMLBuilder(SAML2AssertionGenerator.java:156)
at com.intuit.ipp.aggcat.util.SAML2AssertionGenerator.createSubject(SAML2AssertionGenerator.java:187)
at com.intuit.ipp.aggcat.util.SAML2AssertionGenerator.buildAssertion(SAML2AssertionGenerator.java:114)
at com.intuit.ipp.aggcat.util.SAML2AssertionGenerator.generateSignedAssertion(SAML2AssertionGenerator.java:83)
at com.intuit.ipp.aggcat.util.SamlUtil.createSignedSAMLPayload(SamlUtil.java:156)
at com.intuit.ipp.aggcat.util.OAuthUtil.getOAuthTokens(OAuthUtil.java:60)
at com.intuit.ipp.aggcat.core.OAuthAuthorizer.<init>(OAuthAuthorizer.java:85)
at com.incomemax.view.intuit.WebUtil.getAggCatService(WebUtil.java:91)
Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Logger
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:305)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:246)
... 64 more
我已经解压缩了XMLConfigurat或者奇怪的是它不导入org.apache.log4j.Logger它使用的是org.slf4j.Logger，它也在我的jars目录中（slf4j-api-1.7.5.jar）。同样有趣的是第60行（参见堆栈跟踪）是我的反编译中的空行。
I decomplied XMLConfigurator and oddly it doesn't import org.apache.log4j.Logger It uses org.slf4j.Logger which is also in my jars directory (slf4j-api-1.7.5.jar). Also interesting is that line 60 (see stack trace) is a blank line in my decompile.
当然如果我在设计时添加Logger.xxxxx，它发现它很好。
Of course if I add Logger.xxxxx during design time, it finds it just fine.
我直接从示例java代码中使用代码/ jar，但导入到我现有的应用程序中。
I'm using the code/jars directly from the sample java code, but imported into my existing application.
我一直在网上搜索答案，我相信我已经检查了所有我能想到的方面。我还引用了这个非常好的页面： http://myarch.com/classnotfound/
I've been scouring the web for answers and I believe I've checked all the areas I can think of. I also referenced this very good page: http://myarch.com/classnotfound/
鉴于授权是使用Intuit Developer API的第1步，我有点卡住了。
Given authorization is step 1 in using the Intuit Developer API, I'm kinda stuck.
从@jhadesdev添加输出建议：
Adding output from @jhadesdev suggestion:
所有版本的log4j Logger：
All versions of log4j Logger:
- zip：C：/ Users / Chris /AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/log4j-1.2.17.jar!/org/ apache / log4j / Logger.class
所有版本的log4j都可以从OAuthAuthorizer类的类加载器中看到：
All versions of log4j visible from the classloader of the OAuthAuthorizer class:
- zip：C：/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee- app / lt5l71 / war / WEB-INF / lib / log4j-1.2.17.jar！/org/apache/log4j/Logger.class
所有版本的XMLConfigurator：
All versions of XMLConfigurator:
-
jar：file：/ C：/Oracle/Middleware11116/modules/com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar！/ org / opensaml / xml / XMLConfigurator.class
jar:file:/C:/Oracle/Middleware11116/modules/com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar!/org/opensaml/xml/XMLConfigurator.class
zip：C：/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/ DefaultServer的/ tmp / _WL_user / J2EE的应用程序/ lt5l71 /战争/ WEB-INF / lib目录/ IPP-java的aggcat-V1的devkit-1.0.2.jar！/org/opensaml/xml/XMLConfigurator.class
zip:C:/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/ipp-java-aggcat-v1-devkit-1.0.2.jar!/org/opensaml/xml/XMLConfigurator.class
zip：C：/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app /lt5l71/war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
zip:C:/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
从OAuthAuthorizer类的类加载器中可以看到所有版本的XMLConfigurator：
All versions of XMLConfigurator visible from the class loader of the OAuthAuthorizer class:
-
jar：file：/ C：/Oracle/Middleware11116/modules/com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar！/org/opensaml/xml/XMLConfigurator.class
jar:file:/C:/Oracle/Middleware11116/modules/com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar!/org/opensaml/xml/XMLConfigurator.class
zip：C：/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61。 92 /默认域/服务器/ DefaultServer的/ tmp / _WL_user / J2EE的应用程序/ lt5l71 /战争/ WEB-INF / lib目录/ IPP-java的aggcat-V1的devkit-1.0.2.jar！/组织/ opensaml / XML / XMLConfigurator .class
zip:C:/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/ipp-java-aggcat-v1-devkit-1.0.2.jar!/org/opensaml/xml/XMLConfigurator.class
zip：C：/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp /_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
zip:C:/Users/Chris/AppData/Roaming/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/tmp/_WL_user/j2ee-app/lt5l71/war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
我仍在努力解释结果。
推荐答案
提出建议@jhadesdev和其他人的解释，我在这里找到了这个问题。
With the suggestions @jhadesdev and the explanations from others, I've found the issue here.
添加代码后，看看各种类加载器可见的内容，我发现了这个： / p>
After adding the code to see what was visible to the various class loaders I found this:
All versions of log4j Logger:
zip:<snip>war/WEB-INF/lib/log4j-1.2.17.jar!/org/apache/log4j/Logger.class
All versions of log4j visible from the classloader of the OAuthAuthorizer class:
zip:<snip>war/WEB-INF/lib/log4j-1.2.17.jar!/org/apache/log4j/Logger.class
All versions of XMLConfigurator:
jar:<snip>com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar!/org/opensaml/xml/XMLConfigurator.class
zip:<snip>war/WEB-INF/lib/ipp-java-aggcat-v1-devkit-1.0.2.jar!/org/opensaml/xml/XMLConfigurator.class
zip:<snip>war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
All versions of XMLConfigurator visible from the classloader of the OAuthAuthorizer class:
jar:<snip>com.bea.core.bea.opensaml2_1.0.0.0_6-1-0-0.jar!/org/opensaml/xml/XMLConfigurator.class
zip:<snip>war/WEB-INF/lib/ipp-java-aggcat-v1-devkit-1.0.2.jar!/org/opensaml/xml/XMLConfigurator.class
zip:<snip>war/WEB-INF/lib/xmltooling-1.3.1.jar!/org/opensaml/xml/XMLConfigurator.class
我注意到另一个版本的XMLConfigurator可能被拿起了。
我对该类进行了反编译并在第60行发现了这一点（错误位于原始堆栈跟踪中） private static final Logger log = Logger.getLogger（XMLConfigurator.class）; 并且该类是从 org.apache.log4j.Logger 导入的！
I noticed that another version of XMLConfigurator was possibly getting picked up.
I decompiled that class and found this at line 60 (where the error was in the original stack trace) private static final Logger log = Logger.getLogger(XMLConfigurator.class); and that class was importing from org.apache.log4j.Logger!
所以这是这个类正在加载和使用。我的修复是重命名包含此文件的jar文件，因为我无法找到我明确或间接加载它的位置。这可能会在我实际部署时出现问题。
So it was this class that was being loaded and used. My fix was to rename the jar file that contained this file as I can't find where I explicitly or indirectly load it. Which may pose a problem when I actually deploy.
感谢您提供所有帮助和课程加载所需的课程。
Thanks for all help and the much needed lesson on class loading.
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