web.xml报错：cvc-complex-type.2.4.a: Invalid content was found starting with element 'async-supported'. One of '{"http://java.sun.com/xml/ns/javaee":init-param}' is expected.

在写xml的时候又一次总是报cvc-complex-type.2.4.a: Invalid content was found starting with element 错误，还出现小红叉，在网上找了很多，有说是把报红叉的代码写在<jsp-config></jsp-config>之间，试了之后发现完全没用。 

   后来在外文网站上找到了一个方法就把问题解决了

 解决办法为：将“http://www.springmodules.org/schema/cache/springmodules-cache.xsd http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd”这段话加入到xml文件的"xmlns:xsi="的标签中

<?xml version="1.0" encoding="UTF-8"?> 

<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"   

  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance 

 http://www.springmodules.org/schema/cache/springmodules-cache.xsd

 http://www.springmodules.org/schema/cache/springmodules-ehcache.xsd"   

 xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee      

http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd ">  

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