Caused by: javax.el.PropertyNotFoundException: Property [userName] not found on type [java.lang.Stri

Caused by: javax.el.PropertyNotFoundException: Property [userName] not found on type [java.lang.String] at javax.el.BeanELResolver$BeanProperties.get(BeanELResolver.java:260) at javax.el.BeanELResolver$BeanProperties.access$300(BeanELResolver.java:212) at javax.el.BeanELResolver.property(BeanELResolver.java:347) at javax.el.BeanELResolver.getValue(BeanELResolver.java:92) at org.apache.jasper.el.JasperELResolver.getValue(JasperELResolver.java:110) at org.apache.el.parser.AstValue.getValue(AstValue.java:169) at org.apache.el.ValueexpressionImpl.getValue(ValueexpressionImpl.java:190) at org.apache.jasper.runtime.PageContextImpl.proprietaryevaluate(PageContextImpl.java:944) at org.apache.jsp.main_jsp._jspService(main_jsp.java:120) at org.apache.jasper.runtime.HttpJspbase.service(HttpJspbase.java:70) at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:476) ... 61 more

意思就是沒有找到el表达式中的属性，检查一下是不是属性名写错了