我正在使用struts进行项目，使用Eclipse Juno和Tomcat 7，当尝试在服务器上运行项目时出现此错误：
HTTP状态500 - java.lang.ClassNotFoundException
以下是描述：
description: The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: java.lang.ClassNotFoundException: com.project.HelloWorldAction
org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:286)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
root cause
java.lang.ClassNotFoundException: com.project.HelloWorldAction
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1713)
org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1558)
org.apache.struts.chain.commands.util.ClassUtils.getApplicationClass(ClassUtils.java:54)
org.apache.struts.chain.commands.util.ClassUtils.getApplicationInstance(ClassUtils.java:71)
org.apache.struts.chain.commands.servlet.CreateAction.createAction(CreateAction.java:98)
org.apache.struts.chain.commands.servlet.CreateAction.getAction(CreateAction.java:68)
org.apache.struts.chain.commands.AbstractCreateAction.execute(AbstractCreateAction.java:91)
org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
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