一、问题来源
今天在部署开发好的组件的时候,发现无法启动,检查启动日志,报如下错误:
2022-03-17T10:39:41.823+08:00 ERROR vediomanage.vediomanage [localhost-startStop-5] [org.springframework.boot.SpringApplication:823] - Application run failed org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [org.springframework.cloud.context.environment.EnvironmentManager@1c68757b] with key 'environmentManager'; nested exception is javax.management.InstanceAlreadyExistsException: org.springframework.cloud.context.environment:name=environmentManager,type=EnvironmentManager at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:625) at org.springframework.jmx.export.MBeanExporter.lambda$registerBeans$2(MBeanExporter.java:551) at java.base/java.util.HashMap.forEach(HashMap.java:1336) at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:551) at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:434) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:863) at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:863) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:546) at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141) at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:744) at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:391) at org.springframework.boot.SpringApplication.run(SpringApplication.java:312) at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:151) at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:131) at org.springframework.boot.web.servlet.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:91) at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:171) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5225) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:754) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:730) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:744) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:1135) at org.apache.catalina.startup.HostConfig$DeployDirectory.run(HostConfig.java:1869) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834) Caused by: javax.management.InstanceAlreadyExistsException: org.springframework.cloud.context.environment:name=environmentManager,type=EnvironmentManager at java.management/com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:436) at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1855) at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:955) at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:890) at java.management/com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:320) at java.management/com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522) at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:137) at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:679) at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:615) ... 27 common frames omitted
二、解决方法
application.properties中添加配置:
spring.jmx.default-domain=vediomanage
问题解决。
三、总结
JMX即Java Management Extension(Java管理应用扩展),这种机制可以方便的管理、监控正在运行的Java程序。常用于监控管理线程、内存、日志Level、服务重启、系统环境等等。springboot中spring.jmx是默认打开的,要求每个JMX域名字必须是唯一的,当两个服务同时部署在同一个tomcat上时,由于都没有指定JMX的域名称,所以会启动报错。