What is reflection and why is it useful?

Reflection is a feature of the Java language that allows you to inspect and manipulate classes, fields, and methods at runtime.

Reflection is useful because it allows you to write code that can interact with the structure and behavior of an application at runtime, rather than being bound to the structure and behavior of the code at compile-time. This can be useful for a variety of purposes, including:

• Debugging: Reflection can be used to inspect the structure and behavior of an application at runtime, which can be helpful for debugging and diagnosing problems.

• Dynamic loading: Reflection can be used to load classes and invoke methods dynamically, which allows you to write code that can interact with unknown or changing code at runtime.

• Framework development: Reflection can be used to build frameworks that can work with a variety of different classes, rather than being tied to a specific set of classes.

• Code generation: Reflection can be used to generate code at runtime, which can be useful for implementing code generators or other tools that need to create code based on inputs at runtime.

Reflection can be powerful, but it can also be slow and can break encapsulation if used improperly. As a result, it is generally best to use reflection only when necessary, and to avoid using it in performance-critical code.