我是ajax的新手，我正在尝试制作一个struts应用程序，它使用ajax来填充其他组合框的更改事件上的组合框。我在互联网上找到code，我尝试运行它，但我得到错误舔
`javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.struts.taglib.html.SelectTag.calculateMatchValues(SelectTag.java:224)
at org.apache.struts.taglib.html.SelectTag.doStartTag(SelectTag.java:177)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:92)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:113)
at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Feb 17, 2012 5:27:54 PM org.apache.struts.chain.commands.AbstractExceptionHandler execute
WARNING: Unhandled exception
org.apache.jasper.JasperException: An exception occurred processing JSP page /showCharacters.jsp at line 25
22: <%} %>
23: </logic:present>
24: </html:select> --%>
25: <html:select property="TVShowSelect">
26: <logic:present name="characters">
27: <%ArrayList<String> ch = (ArrayList<String>) request.getSession().getAttribute("characters");
28:
Stacktrace:
at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:519)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:410)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:113)
at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.servlet.ServletException: javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:865)
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:794)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:171)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
... 33 more
Caused by: javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.struts.taglib.html.SelectTag.calculateMatchValues(SelectTag.java:224)
at org.apache.struts.taglib.html.SelectTag.doStartTag(SelectTag.java:177)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:92)
... 36 more
Feb 17, 2012 5:27:54 PM org.apache.struts.chain.commands.ExceptionCatcher postprocess
WARNING: Exception from exceptionCommand 'servlet-exception'
org.apache.jasper.JasperException: An exception occurred processing JSP page /showCharacters.jsp at line 25
22: <%} %>
23: </logic:present>
24: </html:select> --%>
25: <html:select property="TVShowSelect">
26: <logic:present name="characters">
27: <%ArrayList<String> ch = (ArrayList<String>) request.getSession().getAttribute("characters");
28:
Stacktrace:
at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:519)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:410)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:113)
at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
Caused by: javax.servlet.ServletException: javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:865)
at org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:794)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:171)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
... 33 more
Caused by: javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.struts.taglib.html.SelectTag.calculateMatchValues(SelectTag.java:224)
at org.apache.struts.taglib.html.SelectTag.doStartTag(SelectTag.java:177)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:92)
... 36 more
Feb 17, 2012 5:27:54 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet action threw exception
javax.servlet.jsp.JspException: Cannot find bean under name org.apache.struts.taglib.html.BEAN
at org.apache.struts.taglib.html.SelectTag.calculateMatchValues(SelectTag.java:224)
at org.apache.struts.taglib.html.SelectTag.doStartTag(SelectTag.java:177)
at org.apache.jsp.showCharacters_jsp._jspService(showCharacters_jsp.java:92)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:386)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:436)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:374)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:302)
at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:113)
at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:617)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Unknown Source)
任何人都可以帮助我
答案 0 :(得分：0)
当onchange事件发生时，使用表单bean存储数据。 因此，只有你会得到这个例外。 和action类应该返回null。组合框将由jsp页面中的div标签动态生成。
答案 1 :(得分：0)
只需添加标记库：
<%@ taglib uri="http://struts.apache.org/tags-bean" prefix="bean" %>
<%@ taglib uri="http://struts.apache.org/tags-html" prefix="html" %>
等并添加jar文件：
struts-taglib-1.3.10
等