Cannot change version of project facet Dynamic Web Module to 3.0 异常问题处理

如何解决Tomcat服务器在初始化应用的时候的以下异常问题

1，Cannot change version of project facet Dynamic Web Module to 3.0

2，One or more constraints have not been satisfied

3，严重: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/....]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)

需要修改 project的 properties的 Project Facts的 Dynamic Web Moudle Version版本和 web.xml中的版本一致，然后 在通过maven update（Alt+F5）

如图所示：如果禁止修改 则在项目的根目录下 \.settings\org.eclipse.wst.common.project.facet.core.xml 里面

修改这一句话： <installed facet="jst.web" version="3.0"/>





以下为 web.xml的各个版本：

web.xml v2.3

[xml] view plain copy





<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE web-app PUBLIC "-//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 v2.4

[xml] view plain copy





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

<web-app id="WebApp_9" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"

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

xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
</web-app>

web.xml v2.5

[xml] view plain copy





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

<web-app xmlns=<a target="_blank" href="http://java.sun.com/xml/ns/javaee">http://java.sun.com/xml/ns/javaee</a>

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

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">

</web-app>

web.xml v3.0

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

<web-app

version="3.0"

xmlns="http://java.sun.com/xml/ns/javaee"

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

xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">
</web-app>