tomcat-use rorg.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload

I find something interesting, when I use myeclipse to deploy web project, I can upload picture successfully, but when I put .war  to tomcat/webapps and startup tomcat, I can't upload picture. And this is tomcat's log:

java.lang.NoSuchMethodError: org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload.parseRequest(Ljavax/servlet/http/HttpServletRequest;)Ljava/util/List; at dao.ImageUploadDao.upload(ImageUploadDao.java:32) at servlet.imageUploadServlet.doPost(imageUploadServlet.java:42) at javax.servlet.http.HttpServlet.service(HttpServlet.java:644) at javax.servlet.http.HttpServlet.service(HttpServlet.java:725) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658) at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:277) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.doRun(AprEndpoint.java:2407) at org.apache.tomcat.util.net.AprEndpoint$SocketProcessor.run(AprEndpoint.java:2396) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:744)

So can somebody tell me why? I think myeclipse may do something in addition. And I have the solution that to use org.apache.commons.fileupload.jar to instead of org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload.jar, the latter is belong to tomcat lib. But I think the solution is to hide the fact,because when I don't export org.apache.commons.fileupload.jar,I use myeclipse to deploy project,is also ok, that illustrates org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload.jar is also ok.