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

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1. <!DOCTYPE web-app PUBLIC  
2. "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"  
3. "http://java.sun.com/dtd/web-app_2_3.dtd" >  
4.   
5. <web-app>  
6.   
7. </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 SpecJSP SpecEL SpecWebSocket SpecJASPIC SpecApache Tomcat versionActual release revisionSupported Java Versions4.0TBD (2.4?)TBD (3.1?)TBD (1.2?)1.19.0.x9.0.0.M9 (alpha)8 and later3.12.33.01.11.18.5.x8.5.47 and later3.12.33.01.1N/A8.0.x (superseded)8.0.35 (superseded)7 and later3.02.22.21.1N/A7.0.x7.0.706 and later
(7 and later for WebSocket)2.52.12.1N/AN/A6.0.x6.0.455 and later2.42.0N/AN/AN/A5.5.x (archived)5.5.36 (archived)1.4 and later2.31.2N/AN/AN/A4.1.x (archived)4.1.40 (archived)1.3 and later2.21.1N/AN/AN/A3.3.x (archived)3.3.2 (archived)1.1 and later