java.lang.IllegalArgumentException:addChild:Child name 'ssi'

java.lang.IllegalArgumentException:addChild:Child name 'ssi' is not unique 感激~
严重:End event threw exception
java.lang.reflect.InvocationTargetException
Caused by:java.lang.IllegalArgumentException:addChild:Child name 'ssi' is not unique
x05at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:781)
x05at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
x05at org.apache.catalina.core.StandardContext.addChild(StandardContext.java:2037)
x05...46 more
2011-9-1 13:56:29 org.apache.catalina.startup.ContextConfig applicationWebConfig
严重:Parse error in application web.xml file at jndi:/localhost/CMS/WEB-INF/web.xml
java.lang.IllegalArgumentException:addChild:Child name 'ssi' is not unique