javax / management / MBeanServer的装入程序约束冲突问题

Question

我正在尝试将应用程序从JBoss-4.0.4.GA迁移到wildfly-10.1.0.Final。 我的JMX有问题。

在启动应用程序期间，我得到以下信息：

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)

为了更精确地实现代码级别，以下代码行产生了上述异常：

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

我创建了带有所需jar列表的模块。 我没有在Wildfly内部修改客户端库。

您有什么想法可以解决这个问题吗？

谢谢阿纳托利

Answer 1

这是错误消息的有趣部分：

加载程序约束违规：加载程序（org / jboss / modules / ModuleClassLoader的实例）先前在以下位置启动了名称为“ javax / management / MBeanServer”的其他类型的加载

潜在的问题在这里进行了更详细的说明。 本文的结论是：

简而言之，如果两个不同的类相互交互，则可能发生链接错误，并且在这种交互中，这些类引用具有相同符号名但具有不同类对象的类型。

不同的类对象源于通过不同的类加载器加载类的事实，因为每个类均由其FQN和（！）加载通过它的类加载器来标识。

请检查您的类路径（在Wildfly / JBoss的modules目录中，甚至在您的部署中）是否没有javax / management / MBeanServer的多个实例。