无法找到XML模式名称空间/ schema / webflow的Spring NamespaceHandler

Question

我是spring和spring webflow的初学者。尝试遵循多元化指南并设置Spring Webflow时，出现以下错误。

30-Jun-2019 11:01:30.975 SEVERE [main] org.springframework.web.context.ContextLoader.initWebApplicationContext Context initialization failed
 org.springframework.beans.factory.parsing.BeanDefinitionParsingException: Configuration problem: Unable to locate Spring NamespaceHandler for XML schema namespace [http://www.springframework.org/schema/webflow]
Offending resource: ServletContext resource [/WEB-INF/bank-flow.xml]

    at org.springframework.beans.factory.parsing.FailFastProblemReporter.error(FailFastProblemReporter.java:72)
    at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:119)
    at org.springframework.beans.factory.parsing.ReaderContext.error(ReaderContext.java:111)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.error(BeanDefinitionParserDelegate.java:281)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1363)
    at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1352)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:185)
    at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:149)

我已经下载了spring webflow，spring绑定和js jar文件，并手动添加到lib文件夹中。我暂时不使用Maven build。有人可以帮忙吗？