The previous development environment was Eclipse (Luna Release (4.4.0) + WTP + Gradle + tomcat 7, which was later planned to be upgraded to Tomcat 8, and the result was that the integrated development environment was not going to go smoothly.
The Oval Red box section is set to be seen directly in the Src/main/webapp directory as the runtime directory of Tomcat, rather than in the default way of not sending Eclipse workspace. Plugin below.
The advantage of this is that you can edit those jsps, CSS, JS directly with the external editor and then refresh them without going back to eclipse (so that the modified files are synced to the target folder).
Because Gradle is used as a JAR package management tool, Web-inf/lib is empty, but the following settings are made on Project eclipse:
These were smooth when mated with Tomcat 7, and the result was not upgraded to Tomcat 8, with the permission to say that the TLD under the jar package could not be found, such as the TLD files under Jstl-1.2.jar.
Later, modify the WTP Server settings to change it to the default publish to. Plugin mode, which is normal.
So you can think that Eclipse's bug,google a lap without finding a good solution, so switch it back to Tomcat 7, residual
The Eclipse Luna WTP's integration with Tomcat 8 has a very troublesome Bug