javax/management/MBeanServer加載程序約束違規問題

Question

我試圖將應用程序從JBoss-4.0.4.GA遷移到wildfly-10.1.0.Final。我遇到了JMX的問題。

在應用程序的啓動時，我發現了以下內容：

10:58:02,689 WARN [org.jboss.modules] (ServerService Thread Pool -- 90) Failed to define class javax.management.MBeanServer in Module "com.xor.genesis:main" from local module loader @1c2c22f3 (finder: local module finder @18e8568 (roots: /home/user/wildfly-10.1.0.Final/modules,/home/user/wildfly-10.1.0.Final/modules/system/layers/base)): java.lang.LinkageError: Failed to link javax/management/MBeanServer (Module "com.xor.genesis:main" from local module loader @1c2c22f3 (finder: local module finder @18e8568 (roots: /home/chaos1/wildfly-10.1.0.Final/modules,/home/chaos1/wildfly-10.1.0.Final/modules/system/layers/base))): loader constraint violation: loader (instance of org/jboss/modules/ModuleClassLoader) previously initiated loading for a different type with name "javax/management/MBeanServer" 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) 
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) 
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 
    at org.jboss.modules.ModuleClassLoader.defineClass(ModuleClassLoader.java:446) 
    at org.jboss.modules.ModuleClassLoader.loadClassLocal(ModuleClassLoader.java:274) 
    at org.jboss.modules.ModuleClassLoader$1.loadClassLocal(ModuleClassLoader.java:78) 
    at org.jboss.modules.Module.loadModuleClass(Module.java:606) 
    at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190) 
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:363) 
    at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:351) 
    at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:93) 
    at com.xor.genesis.core.jmx.framework.ApplicationMBeanManager.registerMBean(ApplicationMBeanManager.java:37) 
    at com.xor.genesis.cgo.listeners.CGOApplicationListener.registerApplicationLogger(CGOApplicationListener.java:161) 
    at com.xor.genesis.cgo.listeners.CGOApplicationListener.initMBeans(CGOApplicationListener.java:112) 
    at com.xor.genesis.cgo.listeners.CGOApplicationListener.contextInitialized(CGOApplicationListener.java:59) 
    at io.undertow.servlet.core.ApplicationListeners.contextInitialized(ApplicationListeners.java:187) 
    at io.undertow.servlet.core.DeploymentManagerImpl$1.call(DeploymentManagerImpl.java:200) 
    at io.undertow.servlet.core.DeploymentManagerImpl$1.call(DeploymentManagerImpl.java:171) 
    at io.undertow.servlet.core.ServletRequestContextThreadSetupAction$1.call(ServletRequestContextThreadSetupAction.java:42) 
    at io.undertow.servlet.core.ContextClassLoaderSetupAction$1.call(ContextClassLoaderSetupAction.java:43) 
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) 
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) 
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) 
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) 
    at io.undertow.servlet.api.LegacyThreadSetupActionWrapper$1.call(LegacyThreadSetupActionWrapper.java:44) 
    at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:234) 
    at org.wildfly.extension.undertow.deployment.UndertowDeploymentService.startContext(UndertowDeploymentService.java:100) 
    at org.wildfly.extension.undertow.deployment.UndertowDeploymentService$1.run(UndertowDeploymentService.java:82) 
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) 
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) 
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) 
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) 
    at java.lang.Thread.run(Thread.java:748) 
    at org.jboss.threads.JBossThread.run(JBossThread.java:320) 

要在代碼級更精確的下面的行是生產上述異常：

MBeanServer server = java.lang.management.ManagementFactory.getPlatformMBeanServer(); 

我創建自己的模塊與所需的罐子清單。我沒有修改野蠅內的客戶端庫。

你有什麼想法可以解決這個問題嗎？

感謝， 阿納託利

Answer 1

這是錯誤消息的有趣的部分：

裝載機約束衝突：裝載機（的 組織/ JBoss的/模塊實例/ ModuleClassLoader）先前啓動加載的 不同類型的名稱爲「javax/management/MBeanServer」

潛在問題解釋爲here更詳細。本文的結論是：

在簡單的話，可能會出現鏈接錯誤，如果兩個不同的類 彼此互動，並在此互動類是指 類型具有相同的符號名稱但不同的類的對象。

不同的類對象來源於類通過不同的類加載器加載的事實，因爲每個類都由它的FQN和（！）加載它的類加載器來標識。

請檢查您的類路徑中是否存在javax/management/MBeanServer的多個實例（位於Wildfly/JBoss的模塊目錄中，甚至在您的部署中）。