tomcat突然启动不了，报错：
警告: Failed to unregister MBean with name [Catalina:j2eeType=Servlet,name=UploadServlet,WebModule=//localhost/,J2EEApplication=none,J2EEServer=none] during component destruction
javax.management.InstanceNotFoundException: Catalina:j2eeType=Servlet,name=UploadServlet,WebModule=//localhost/,J2EEApplication=none,J2EEServer=none
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(DefaultMBeanServerInterceptor.java:1095)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.exclusiveUnregisterMBean(DefaultMBeanServerInterceptor.java:427)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.unregisterMBean(DefaultMBeanServerInterceptor.java:415)
at com.sun.jmx.mbeanserver.JmxMBeanServer.unregisterMBean(JmxMBeanServer.java:546)
at org.apache.catalina.util.LifecycleMBeanBase.unregister(LifecycleMBeanBase.java:194)
at org.apache.catalina.util.LifecycleMBeanBase.destroyInternal(LifecycleMBeanBase.java:73)
at org.apache.catalina.core.ContainerBase.destroyInternal(ContainerBase.java:1247)
at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:305)
at org.apache.catalina.core.ContainerBase.removeChild(ContainerBase.java:1041)
at org.apache.catalina.core.StandardContext.removeChild(StandardContext.java:4123)
at org.apache.catalina.startup.ContextConfig.configureStop(ContextConfig.java:941)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:395)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
at org.apache.catalina.core.Stand
然后怎么tomcat都启动不了，查了半天，找到解决办法：
就是
jdk的jre/lib/security/java.policy 里加上
permission javax.management.MBeanTrustPermission "register";
另外就是要kill 掉所有tomcat的进程，使用shutdown -force。
重启OK！
