BeanUtils.populate

 javax.servlet.ServletException: BeanUtils.populate
    org.apache.struts.util.RequestUtils.populate(RequestUtils.java:495)
    org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:816)
    org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:203)
    org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    netctoss.filter.MyFilter.doFilter(MyFilter.java:27)

root cause

org.apache.commons.beanutils.ConversionException
    org.apache.commons.beanutils.converters.SqlDateConverter.convert(SqlDateConverter.java:117)
    org.apache.commons.beanutils.ConvertUtilsBean.convert(ConvertUtilsBean.java:428)
    org.apache.commons.beanutils.BeanUtilsBean.setProperty(BeanUtilsBean.java:1004)
    org.apache.commons.beanutils.BeanUtilsBean.populate(BeanUtilsBean.java:811)
    org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:298)
    org.apache.struts.util.RequestUtils.populate(RequestUtils.java:493)
    org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:816)
    org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:203)
    org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
    org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    netctoss.filter.MyFilter.doFilter(MyFilter.java:27)


解决办法：经分析和排错后发现原来是ActionForm 中的实体类没有实例化：private Date beginDate；改成正确的写法是

　private Date beginDate = new Date(0);;然后再加上相应的get和set方法，问题就解决了。