问题
I can run a Spring boot application by deploying its war in an external Tomcat 8.5, but cannot run the same from Spring Tool Suite.
I have a Spring boot application with packaging set to war. I can generate the war file, deploy it to an external tomcat with version 8.5.34. But I cannot run this application using Spring Tool Suite. When I right click on the project > Run As > Run on Server, I get the following dialog box
When I select Tomcat 8.5, the next and finish buttons are disabled. The Server name box is disabled as well. It works fine when selecting Tomcat 9 though.
If I try to edit the Server's host name, I can see a message appear in the dialog box that says The server does not support version 4.0 of the J2EE Web module specification
If I am able to run the application in an external tomcat, why not in an embedded one?
来源：https://stackoverflow.com/questions/53975657/unable-to-choose-tomcat-8-5-in-spring-tool-suite-when-running-spring-boot-applic