1. A class in a dependent jar package is used in the scene
project. If we want to use this class, we need to introduce the jar of this class into our project, so in the MANIFEST.MF file Add a dependency project package (jar) to the startup program, and this exception occurs.
2. Analyze the reason that
the application cannot find and load this class
3. Solve the problem
of adding the project to the startup component, or introducing the jar package of this class