spring-boot: JMX InstanceAlreadyExistsException when setting server.contextPath + dev tools + cloud + actuator

Hi,

I’m having some funnies with the dev tools reload and MBean registration.

Within eclipse, if you create a Spring Boot 1.4.1 Starter Project with the following dependencies: Actuator, Cloud Boostrap, Web & DevTools.

Then add server.contextPath=/webapp to application.properties.

If you trigger a dev tools reload (I just put a comment in the application.properties) then you get the following error

org.springframework.context.ApplicationContextException: Failed to register LiveBeansView MBean; nested exception is javax.management.InstanceAlreadyExistsException: DefaultDomain:application=
    at org.springframework.context.support.LiveBeansView.registerApplicationContext(LiveBeansView.java:72) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishRefresh(AbstractApplicationContext.java:880) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.builder.SpringApplicationBuilder.run(SpringApplicationBuilder.java:134) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.bootstrapServiceContext(BootstrapApplicationListener.java:138) ~[spring-cloud-context-1.1.3.RELEASE.jar:1.1.3.RELEASE]
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:84) ~[spring-cloud-context-1.1.3.RELEASE.jar:1.1.3.RELEASE]
    at org.springframework.cloud.bootstrap.BootstrapApplicationListener.onApplicationEvent(BootstrapApplicationListener.java:62) ~[spring-cloud-context-1.1.3.RELEASE.jar:1.1.3.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:121) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    at org.springframework.boot.context.event.EventPublishingRunListener.environmentPrepared(EventPublishingRunListener.java:68) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplicationRunListeners.environmentPrepared(SpringApplicationRunListeners.java:54) ~[spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.prepareEnvironment(SpringApplication.java:337) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:308) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.1.RELEASE.jar:1.4.1.RELEASE]
    at com.example.SpringDevtoolsIssue2Application.main(SpringDevtoolsIssue2Application.java:11) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.4.1.RELEASE.jar:1.4.1.RELEASE]
Caused by: javax.management.InstanceAlreadyExistsException: DefaultDomain:application=
    at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437) ~[na:1.8.0_101]
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898) ~[na:1.8.0_101]
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966) ~[na:1.8.0_101]
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900) ~[na:1.8.0_101]
    at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324) ~[na:1.8.0_101]
    at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522) ~[na:1.8.0_101]
    at org.springframework.context.support.LiveBeansView.registerApplicationContext(LiveBeansView.java:68) ~[spring-context-4.3.3.RELEASE.jar:4.3.3.RELEASE]
    ... 24 common frames omitted

If I remote debug LiveBeansView then within registerApplicationContext > applicationContext.getApplicationName() returns “” but unregisterApplicationContext > applicationContext.getApplicationName() returns “/webapp” i.e from server.contextPath. Therefore you get a “Failed to unregister LiveBeansView MBean” because it can’t find it.

Thanks

N.B Interestingly if I try and turn off JMX (spring.jmx.enabled=false) this has no effect.