Eclipse error ... cannot be resolved to a type

1. Right click your project name.

2. Click Properties.

3. Click Java Build Path.

4. Click on Add Class Folder.

5. Then choose your class.

Alternatively, Add Jars should work although you claim that you attempted that.

Also, "have you tried turning it off and back on again"? (Restart Eclipse).

Also If you are using mavenised project then try to update your project by clicking Alt+F5. Or right click on the application and go to maven /update project.

It builds all your components and resolves if any import error is there.