End event threw exception

1.   严重: End event threw exception
java.lang.IllegalArgumentException: Can't convert argument: null
 
出现这个异常的时候，不要乱想，不要以为是jar包错误，而是由于xml配置文件解析错误引起的。
首先应该检查配置文件的正确性。以我自己遇到的例子为例：
在web.xml配置文件中引入spring时，写了这样一句错误的配置。
 <!-- 加载spring -->
 <context-param>
  <param-name>contextConfigLocation</param-name>
  <param-name>classpath:applicationContext.xml</param-name>
 </context-param>
其实就错在标注为红色的这一句配置上面,应该配置为:
<param-value>classpath:applicationContext.xml</param-value>

2.java.lang.IllegalArgumentException: Can't convert argument: null
信息: Starting Servlet Engine: Apache Tomcat/6.0.20
2012-6-26 11:09:51 org.apache.tomcat.util.digester.Digester endElement
严重: End event threw exception
java.lang.IllegalArgumentException: Can't convert argument: null
    at org.apache.tomcat.util.IntrospectionUtils.convert(IntrospectionUtils.java:1002)
    at org.apache.tomcat.util.digester.CallMethodRule.end(CallMethodRule.java:523)
    at org.apache.tomcat.util.digester.Rule.end(Rule.java:229)
    at org.apache.tomcat.util.digester.Digester.endElement(Digester.java:1140)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.endElement(AbstractSAXParser.java:601)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanEndElement(XMLDocumentFragmentScannerImpl.java:1774)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2930)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:8)
    at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:510)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:807)
    at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737)
    at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:107)
    at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205)
    at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522)
    at org.apache.tomcat.util.digester.Digester.parse(Digester.java:14)
    at org.apache.catalina.startup.ContextConfig.applicationWebConfig(ContextConfig.java:365)
    at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1066)
 
上述问题是由于在Eclipse下重构JEE项目名时，Eclipse自动更新了部署文件web.xml,重新生成了xml文件的头部声明，新增加了javaee的命名空间
可以把javaee字去掉，就可以了。