Cannot change version of project facet Dynamic Web Module to 3.0.

找到项目下org.eclipse.wst.common.project.facet.core.xml  xml文件

<?xml version="1.0" encoding="UTF-8"?>
<faceted-project>
  <fixed facet="wst.jsdt.web"/>
  <installed facet="jst.web" version="2.3"/>
  <installed facet="wst.jsdt.web" version="1.0"/>
  <installed facet="java" version="1.7"/>
</faceted-project>

将jst.web，的version改成3.0.

然后在eclipse里右键该工程--maven--updateProject

Cannot change version of project facet Dynamic Web Module to 3.0.

原文：http://www.cnblogs.com/damonfirstblog/p/5764577.html