1.tomcat9中報錯
... 37 more
Caused by: org.springframework.jmx.export.UnableToRegisterMBeanException: Unable to register MBean [com.alibaba.druid.filter.stat.StatFilter@1dbef693] with key 'statFilter'; nested exception is javax.management.InstanceAlreadyExistsException: com.alibaba.druid.filter.stat:name=statFilter,type=StatFilter
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:628)
at org.springframework.jmx.export.MBeanExporter.registerBeans(MBeanExporter.java:550)
at org.springframework.jmx.export.MBeanExporter.afterSingletonsInstantiated(MBeanExporter.java:432)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:781)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:314)
at org.springframework.boot.web.support.SpringBootServletInitializer.run(SpringBootServletInitializer.java:151)
at org.springframework.boot.web.support.SpringBootServletInitializer.createRootApplicationContext(SpringBootServletInitializer.java:131)
at org.springframework.boot.web.support.SpringBootServletInitializer.onStartup(SpringBootServletInitializer.java:86)
at org.springframework.web.SpringServletContainerInitializer.onStartup(SpringServletContainerInitializer.java:169)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5139)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
... 38 more
Caused by: javax.management.InstanceAlreadyExistsException: com.alibaba.druid.filter.stat:name=statFilter,type=StatFilter
at com.sun.jmx.mbeanserver.Repository.addMBean(Repository.java:437)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerWithRepository(DefaultMBeanServerInterceptor.java:1898)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerDynamicMBean(DefaultMBeanServerInterceptor.java:966)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerObject(DefaultMBeanServerInterceptor.java:900)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.registerMBean(DefaultMBeanServerInterceptor.java:324)
at com.sun.jmx.mbeanserver.JmxMBeanServer.registerMBean(JmxMBeanServer.java:522)
at org.springframework.jmx.support.MBeanRegistrationSupport.doRegister(MBeanRegistrationSupport.java:195)
at org.springframework.jmx.export.MBeanExporter.registerBeanInstance(MBeanExporter.java:674)
at org.springframework.jmx.export.MBeanExporter.registerBeanNameOrInstance(MBeanExporter.java:618)
... 53 more
2.解決
首先看報錯說的是InstanceAlreadyExistsException，也就是StatFilter（Druid內置用於統計監控信息的）實例已經起了，在啓動報重複異常。
一開始想的是重啓tomcat但是之前的進程沒關閉，然而ps -ef|grep tomcat 後發現就一個tomcat起着。
然後查看啓動日誌：
發現啓動日誌很長，而且有兩次初始連接池的情況，理所當然報錯了
然後想到之前對tomcat的server.xml進行了修改：
因爲註冊了一個域名，但是又想直接域名就能訪問到項目主頁，又不想通過代理轉發的方式，所以修改了server.xml
一開始是這樣配置的：
<Host name="www.cthlizi.cn" appBase="webapps"
unpackWARs="true" autoDeploy="true">
<Context docBase="gmweb" path="" reloadable="false" />
這邊的appBase="webapps"會導致tomcat加載一次應用，然後有配置了Context ，其中docBase又會導致加載一次應用
所以需要修改這裏的配置，參照上面大圖
最後再次重啓tomcat發現沒有異常了，也不影響我的要求。
ps:http://www.cthlizi.cn/ 準備弄個人網站，慢慢搭建中…