Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/flex]

Problem

As I integrated flex with spring framework, I got this error message when I start apache tomcat:

1:  2010/1/20 下午 04:25:59 org.apache.catalina.core.ApplicationContext log  
2:  資訊: Initializing Spring FrameworkServlet 'spring-flex'  
3:  2010/1/20 下午 04:26:00 org.apache.catalina.core.ApplicationContext log  
4:  嚴重的: StandardWrapper.Throwable  
5:  org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/flex]  
6:  Offending resource: ServletContext resource [/WEB-INF/flex-servlet-context.xml]  
7:   at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:68)  
8:   at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:85)  

Solution

This error resulted from I forgot to copy flex-spring integration jar file into WebContent/WEB-INF/lib, you can go to here to download this jar file: http://www.springsource.org/spring-flex