Error creating form bean of class comm.yamma.pojo.DayUser
找了半天还是报错 太郁闷了 自己是整部明白了 来几个明白人吧   
Error creating form bean of class comm.yamma.pojo.DayUser
java.lang.NullPointerException	at org.apache.struts.config.FormBeanConfig.createActionForm(FormBeanConfig.java:212)
	at org.apache.struts.util.RequestUtils.createActionForm(RequestUtils.java:292)
	at org.apache.struts.util.RequestUtils.createActionForm(RequestUtils.java:191)
	at org.apache.struts.taglib.html.FormTag.initFormBean(FormTag.java:477)
	at org.apache.struts.taglib.html.FormTag.doStartTag(FormTag.java:457)
	at org.apache.jsp.usercount.userReportDaily_jsp._jspx_meth_html_005fform_005f0(userReportDaily_jsp.java:168)
	at org.apache.jsp.usercount.userReportDaily_jsp._jspService(userReportDaily_jsp.java:80)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:98)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:328)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:315)
	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 com.yamma.filter.MyFilter.doFilter(MyFilter.java:38)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at com.yamma.filter.ControlLogFilter.doFilter(ControlLogFilter.java:148)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:215)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
	at com.yamma.filter.Filter.doFilter(Filter.java:24)
	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:210)
	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:870)
	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:685)
	at java.lang.Thread.run(Thread.java:595)
2008-12-3 18:57:03 org.apache.catalina.core.StandardWrapperValve invoke
严重: 
Servlet.service() for servlet jsp threw exceptionjavax.servlet.jsp.JspException: Exception creating bean of class comm.yamma.pojo.DayUser: {1}
	at org.apache.struts.taglib.html.FormTag.initFormBean(FormTag.java:487)
	at org.apache.