javax.servlet.ServletException: BeanUtils.populate

java.lang.IllegalArgumentException: argument type mismatch
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
java.lang.reflect.Method.invoke(Unknown Source)
org.apache.commons.beanutils.PropertyUtils.setSimpleProperty(PropertyUtils.java:1789)
org.apache.commons.beanutils.PropertyUtils.setNestedProperty(PropertyUtils.java:1684)
org.apache.commons.beanutils.PropertyUtils.setProperty(PropertyUtils.java:1713)
org.apache.commons.beanutils.BeanUtils.setProperty(BeanUtils.java:1019)
org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:808)
org.apache.struts.util.RequestUtils.populate(RequestUtils.java:495)
org.apache.struts.action.RequestProcessor.processPopulate(RequestProcessor.java:798)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:205)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1164)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:415)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
cn.rhui.framework.common.filter.ValidationUsersFilter.doFilter(ValidationUsersFilter.java:34)
cn.rhui.framework.common.filter.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter

在Struts开发中遇到了这个问题：javax.servlet.ServletException: BeanUtils.populate
产生这个异常的主要有2点原因：

1.JSP页面是Sing 类型的,如果actionForm里头的数据定义成别的类型,就会报这个错误。

2.JSP页面的字段什么写错了。