故障码:
严重: Servlet.service() for servlet jsp threw exception org.apache.jasper.JasperException: Cannot find any information on property 'User' in a bean of type 'com.entity.user' at org.apache.jasper.runtime.JspRuntimeLibrary.getReadMethod(JspRuntimeLibrary.java:839) at org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1117) at org.apache.jasper.compiler.Node$GetProperty.accept(Node.java:1124) at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361) at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2411) at org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2417) at org.apache.jasper.compiler.Node$Root.accept(Node.java:495) at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2361) at org.apache.jasper.compiler.Generator.generate(Generator.java:3426) at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:216) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:332) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:312) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:299) at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:586) at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:317) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267) at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
没故障的源代码:
user.java源代码:
package com.entity;
public class user {
	
	private String user="zhangsan";
	public String getUser() {
		return user;
	}
	public void setUser(String user) {
		this.user = user;
	}
	
}
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	
  </head>
  
  <body>
  
  <hr>
  这里是JavaBean取值<br>
  <jsp:useBean id="us" class="com.entity.user" scope="page"></jsp:useBean>
  <jsp:getProperty property="user" name="us"/><br>
  <hr>
  
  这里是Java取值<br>
  <%=us.getUser() %><br>
  <hr>
 
  </body>
</html>
当我们将实体类user.java中的属性user改成User时,此时再get/set
更改过后的user.java源代码:
package com.entity;
public class user {
	
	private String User="zhangsan";
	public String getUser() {
		return User;
	}
	public void setUser(String user) {
		User = user;
	}
	
}
其实正确的解决办法是index.jsp页面什么也不需要动,因为user.java虽然将属性user变成User,但是其实属性的get/set方法仍然是不变的,也就是说只要是get/set方法不变,无论是user还是User,在前台jsp页面来看其实都是一样的,所以说前台页面不需要任何改变。
当然如果说用jsp页面内嵌Java代码的方式来取值就不会出现这种问题了(即采用<%=us.getUser()%>的方式),因为此时的取值方式是系统提示生成的,此时就会避免这种问题的发生。
Cannot find any information on property 'User' in a bean of type 'com.entity.user'
原文:http://blog.csdn.net/zzy1078689276/article/details/46458239