Caused by: java.lang.IllegalArgumentException: addChild: Child name 'localhost' is not unique

1、错误描述

严重: End event threw exception
java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.tomcat.util.IntrospectionUtils.callMethod1(IntrospectionUtils.java:852)
	at org.apache.tomcat.util.digester.SetNextRule.end(SetNextRule.java:201)
	at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1060)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(Unknown Source)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(Unknown Source)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(Unknown Source)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(Unknown Source)
	at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
	at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(Unknown Source)
	at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(Unknown Source)
	at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(Unknown Source)
	at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(Unknown Source)
	at org.apache.tomcat.util.digester.Digester.parse(Digester.java:1555)
	at org.apache.catalina.startup.Catalina.load(Catalina.java:615)
	at org.apache.catalina.startup.Catalina.load(Catalina.java:663)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
	at java.lang.reflect.Method.invoke(Unknown Source)
	at org.apache.catalina.startup.Bootstrap.load(Bootstrap.java:280)
	at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:454)
Caused by: java.lang.IllegalArgumentException: addChild:  Child name 'localhost' is not unique
	at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:887)
	at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
	at org.apache.catalina.core.StandardEngine.addChild(StandardEngine.java:244)
	... 26 more

2、错误原因

     由于在Tomcat中的server.xml中加了一个：

<Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true"></Host>

    而自身本来自带一个：

<Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true"></Host>

     有两个Host导致重复

3、解决办法

    去掉添加的一个Host

<Host appBase="webapps" autoDeploy="true" name="localhost" unpackWARs="true"></Host>