场景：
最近在一个新项目的依赖包调整过程中，引入包之后，发现项目启动报错，一直启动不成功，经过查询和排查，发现是包对xml解析冲突的问题；
报错信息：
[WARNING] Nested in org.springframework.beans.factory.xml.XmlBeanDefinitionStoreException: Line 24 in XML document from URL [file:xxxxxxx/target/classes/web-servlet.xml] is invalid; nested exception is org.xml.sax.SAXParseException; systemId: http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd; lineNumber: 24; columnNumber: 20; cos-all-limited.1.2: An ''all'' model group must appear in a particle with '{'min occurs'}'='{'max occurs'}'=1, and that particle must be part of a pair which constitutes the '{'content type'}' of a complex type definition.:
org.xml.sax.SAXParseException: cos-all-limited.1.2: An ''all'' model group must appear in a particle with '{'min occurs'}'='{'max occurs'}'=1, and that particle must be part of a pair which constitutes the '{'content type'}' of a complex type definition.
at org.apache.xerces.parsers.DOMParser.parse (DOMParser.java:267)
at org.apache.xerces.jaxp.DocumentBuilderImpl.parse (DocumentBuilderImpl.java:201)
at org.springframework.beans.factory.xml.DefaultDocumentLoader.loadDocument (DefaultDocumentLoader.java:76)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadDocument (XmlBeanDefinitionReader.java:429)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions (XmlBeanDefinitionReader.java:391)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions (XmlBeanDefinitionReader.java:336)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions (XmlBeanDefinitionReader.java:304)
at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions (AbstractBeanDefinitionReader.java:181)
排查步骤：
1. 是不是报错信息中的xml写错了配置；
2. 包冲突， 从错误堆栈中可以看到 xerces 包的DOMParser，猜测是 xerces 和 Spring的对于xml的解析出现了冲突，然后将xerces包中项目中排除（包括直接依赖和传递依赖）
结果：
发现是包冲突了，去掉common-pool的传递依赖的xerces包，问题解决。