Struts异常：Cannot retrieve definition for form bean

编译Struts文件出现的异常：

org.apache.jasper.JasperException: Cannot retrieve definition for form bean yesnoQuestionForm on action /yesnoquestion
    at org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:460)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:355)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:265)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:691)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:469)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:403)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:301)
    at org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1063)
    at org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:386)
    at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:229)
    at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1194)
    at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at com.wyu.exam.filter.EncodingFilter.doFilter(EncodingFilter.java:90)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at com.wyu.exam.filter.HibernateFilter.doFilter(HibernateFilter.java:39)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
    at org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    at java.lang.Thread.run(Thread.java:619)

错误分析：编码书写规范错误。struts.xml原文件的部分代码

 
 
          name="classesForm"
      type="com.wyu.exam.form.ClassesForm"
     />
   ......

         name="yesnoQuestionForm"
      type="com.wyu.exam.form.YesnoQuestionForm"
    />
解决方法：

修改struts.xml文件，把..移到..里面

 
 
          name="classesForm"
      type="com.wyu.exam.form.ClassesForm"
     />
   ......

         name="yesnoQuestionForm"
      type="com.wyu.exam.form.YesnoQuestionForm"
    />