SpringMVC中JSP取不到ModelAndView的数据原因

因为maven自动生成的web.xml文件的版本为v2.3的，如下，与使用的servlet和tomcat不匹配；需要将版本改为v2.5以上版本

web.xml v2.3

 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

 <web-app>

 web-app>

web.xml v2.5

 1 xml version="1.0" encoding="UTF-8"?>  
 2    
 3 <web-app xmlns="http://java.sun.com/xml/ns/javaee"  
 4    
 5 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
 6    
 7 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"  
 8    
 9 version="2.5">  
10    
11 web-app>

或 web.xml v3.0

1 xml version="1.0" encoding="UTF-8"?>  
2    
3 <web-app  
4         version="3.0"  
5         xmlns="http://java.sun.com/xml/ns/javaee"  
6         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
7         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">  
8    
9 web-app>

 不同的头信息，代表不同的servlet版本和tomcat版本

Servlet Spec	JSP Spec	EL Spec	WebSocket Spec	JASPIC Spec	Apache Tomcat version	Actual release revision	Supported Java Versions
4.0	TBD (2.4?)	TBD (3.1?)	TBD (1.2?)	1.1	9.0.x	9.0.0.M9 (alpha)	8 and later
3.1	2.3	3.0	1.1	1.1	8.5.x	8.5.4	7 and later
3.1	2.3	3.0	1.1	N/A	8.0.x (superseded)	8.0.35 (superseded)	7 and later
3.0	2.2	2.2	1.1	N/A	7.0.x	7.0.70	6 and later (7 and later for WebSocket)
2.5	2.1	2.1	N/A	N/A	6.0.x	6.0.45	5 and later
2.4	2.0	N/A	N/A	N/A	5.5.x (archived)	5.5.36 (archived)	1.4 and later
2.3	1.2	N/A	N/A	N/A	4.1.x (archived)	4.1.40 (archived)	1.3 and later
2.2	1.1	N/A	N/A	N/A	3.3.x (archived)	3.3.2 (archived)	1.1 and later