java - I am a beginner in SSM. I became famous when I imported classes under a package I wrote. Can someone please give me an answer?

Question

1.SSM framework, when importing packages, it becomes red, and pom dependencies are imported correctly.
2. It is useless to click clean in the project and then click install.
3.

4.

Answer 1

The com.tustcs.matrix package was created by me in the folder

, so an error was reported!
Let’s review the naming convention of JAVA packages...

Answer 2

First check if your package is in the lib directory. If not, it means there is a maven import error. If there is, open the project settings and see if the project uses the package.

Answer 3

For local jar packages, search how to use local jar packages in maven