问题
在配置log4j2的时候，在resources目录下添加了log4j2.xml，前两行的内容如下：
<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="WARN">
项目启动后报错500，报错信息如下：
javax.servlet.ServletException: Servlet.init() for servlet springmvc threw exception
org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 30; cvc-elt.1: Cannot find the declaration of element 'Configuration'.
org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
org.apache.xerces.impl.xs.XMLSchemaValidator.handleStartElement(Unknown Source)
org.apache.xerces.impl.xs.XMLSchemaValidator.startElement(Unknown Source)
HTTP Status 500 - Servlet.init() for servlet springmvc threw exception
type Exception report
message Servlet.init() for servlet springmvc threw exception
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Servlet.init() for servlet springmvc threw exception
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2527)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2516)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:748)
root cause
org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 2 in XML document from file [E:\Workspaces\GitYonyou\gate\target\gate-0.1-SNAPSHOT\WEB-INF\classes\log4j2.xml] is invalid; nested exception is org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 30; cvc-elt.1.a: Cannot find the declaration of element 'Configuration'.
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:405)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:337)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:305)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:224)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:195)
org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:133)
org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:637)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:522)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:702)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:668)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:716)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:591)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:530)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:170)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2527)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2516)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:748)
root cause
org.xml.sax.SAXParseException; lineNumber: 2; columnNumber: 30; cvc-elt.1.a: Cannot find the declaration of element 'Configuration'.
org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
org.apache.xerces.impl.xs.XMLSchemaValidator.handleStartElement(Unknown Source)
org.apache.xerces.impl.xs.XMLSchemaValidator.startElement(Unknown Source)
org.apache.xerces.impl.XMLNSDocumentScannerImpl.scanStartElement(Unknown Source)
org.apache.xerces.impl.XMLNSDocumentScannerImpl$NSContentDispatcher.scanRootElementHook(Unknown Source)
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl$FragmentContentDispatcher.dispatch(Unknown Source)
org.apache.xerces.impl.XMLDocumentFragmentScannerImpl.scanDocument(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XML11Configuration.parse(Unknown Source)
org.apache.xerces.parsers.XMLParser.parse(Unknown Source)
org.apache.xerces.parsers.DOMParser.parse(Unknown Source)
org.apache.xerces.jaxp.DocumentBuilderImpl.parse(Unknown Source)
org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument(DefaultDocumentLoader.java:77)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument(XmlBeanDefinitionReader.java:435)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:393)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:337)
org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:305)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:188)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:224)
org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:195)
org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:125)
org.springframework.web.context.support.XmlWebApplicationContext.loadBeanDefinitions(XmlWebApplicationContext.java:94)
org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:133)
org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:637)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:522)
org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:702)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:668)
org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:716)
org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:591)
org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:530)
org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:170)
javax.servlet.GenericServlet.init(GenericServlet.java:158)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:620)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:502)
org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1132)
org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:684)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2527)
org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2516)
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
java.lang.Thread.run(Thread.java:748)
note The full stack trace of the root cause is available in the Apache Tomcat/8.0.47 logs.