用Eclipse创建Maven结构的web项目的时候选择了Artifact Id为maven-artchetype-webapp，由于这个catalog比较老，用的servlet还是2.3的，而一般现在都是用3.0，在Project Facets里面修改Dynamic web module为3.0的时候就会出现Cannot change version of project facet Dynamic web module to 3.0，如图：
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="schedule-console" version="3.0">eclipse.preferences.version=1org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabledorg.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8org.eclipse.jdt.core.compiler.compliance=1.8org.eclipse.jdt.core.compiler.problem.assertIdentifier=errororg.eclipse.jdt.core.compiler.problem.enumIdentifier=errororg.eclipse.jdt.core.compiler.problem.forbiddenReference=warningorg.eclipse.jdt.core.compiler.source=1.8
<?xml version="1.0" encoding="UTF-8"?><faceted-project> <fixed facet="wst.jsdt.web"/> <installed facet="jst.web" version="3.0"/> <installed facet="wst.jsdt.web" version="1.0"/> <installed facet="java" version="1.8"/></faceted-project>Cannot change version of project facet Dynamic web的解决方法
原文：http://www.cnblogs.com/yieryi/p/6246502.html