照着文档写了个例子，可是执行后没有反应，也没导入成功，帮忙看一下

Dao dao = new NutDao();
            InputStream in = Files.findFileAsStream(Disks.absolute("D:\\www\\用户数据.xlsx"));
            List<Sys_user> people = J4E.fromExcel(in, Sys_user.class, null);
            dao.clear(Sys_user.class);
            dao.insert(people);

以下是日志

java.lang.NoClassDefFoundError: org/apache/poi/ss/usermodel/Workbook
	at cn.wizzer.app.web.modules.controllers.platform.sys.SysUserController.pladdDo(SysUserController.java:152)
	at cn.wizzer.app.web.modules.controllers.platform.sys.SysUserController$FM$pladdDo$da810e841258c3a84ae9124e6d872cd8.invoke(SysUserController.java)
	at org.nutz.mvc.impl.processor.MethodInvokeProcessor.process(MethodInvokeProcessor.java:31)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.AdaptorProcessor.process(AdaptorProcessor.java:38)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.ActionFiltersProcessor.process(ActionFiltersProcessor.java:58)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at cn.wizzer.app.web.commons.processor.XssSqlFilterProcessor.process(XssSqlFilterProcessor.java:35)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at cn.wizzer.app.web.commons.processor.NutShiroProcessor.process(NutShiroProcessor.java:52)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.ModuleProcessor.process(ModuleProcessor.java:123)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.EncodingProcessor.process(EncodingProcessor.java:27)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at org.nutz.mvc.impl.processor.UpdateRequestAttributesProcessor.process(UpdateRequestAttributesProcessor.java:15)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at cn.wizzer.app.web.commons.processor.GlobalsSettingProcessor.process(GlobalsSettingProcessor.java:49)
	at org.nutz.mvc.impl.processor.AbstractProcessor.doNext(AbstractProcessor.java:44)
	at cn.wizzer.app.web.commons.processor.LogTimeProcessor.process(LogTimeProcessor.java:21)
	at org.nutz.mvc.impl.NutActionChain.doChain(NutActionChain.java:44)
	at org.nutz.mvc.impl.ActionInvoker.invoke(ActionInvoker.java:67)
	at org.nutz.mvc.ActionHandler.handle(ActionHandler.java:31)
	at org.nutz.mvc.NutFilter.doFilter(NutFilter.java:202)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:449)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:365)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:383)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:362)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
	at cn.wizzer.app.web.commons.filter.RouteFilter.doFilter(RouteFilter.java:31)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
	at org.nutz.mvc.WhaleFilter.doFilter(WhaleFilter.java:171)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1602)
	at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:214)
	at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1610)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:540)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
	at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1711)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1347)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:480)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1678)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1249)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
	at org.eclipse.jetty.server.Server.handle(Server.java:505)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:370)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:267)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:305)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
	at org.eclipse.jetty.io.ChannelEndPoint$2.run(ChannelEndPoint.java:117)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:781)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:917)
	at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.ClassNotFoundException: org.apache.poi.ss.usermodel.Workbook
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
	... 69 common frames omitted