If we rely on the class name — what restrictions will there be when extending?

When relying on class names during extension, the following limitations arise:

• Tight coupling with a specific implementation. Changing the class name or renaming it requires updating all places where it is used.
• Support and refactoring issues. Using string class names complicates automatic code checking and refactoring.
• Limited flexibility. It is not easy to substitute implementations without changing the name, which hampers extensibility and the introduction of new versions.
• Potential runtime errors. If the class name is incorrect, errors will only appear at runtime, not at compile time.

In Java, it is generally recommended to use class references through types or interfaces rather than string names to ensure type safety and ease of maintenance.