Eclipse中经常弹出Several ports (8005, 8888, 8009) required by Tomcat v9.0 Server at localhost are already in use. The server may already be running in another process, or a system process may be using the port. To start this server you will need to stop the other pro等问题，解决方法可以看看诸如index.jsp等文件是否在webcontent中，就是很不容易注意到的问题，很有可能导致the selection did not contain any resources等问题，