There are no resources that can be added or removed from the server

There are no resources that can be added or removed from the server.
eclipse导入一个项目后，不能加载到tomcat里面，出现“There are no resources that can be added or removed from the server.”

解决方法：
第1步、新建一个“Dynamic Web Project”

第2步、把新建项目里面的.project文件和.settings文件夹复制到导入的那个项目里面。