Design an application that illustrates the following concepts in Java:

1. Strings and at least one other data type.
2. Repetition Statements (including nested loops).
3. Switch Statement (menu of choices is required).
4. Arrays (including array of objects).
5. Exceptions Handling.
6. Classes.
7. Methods (both static and instance, minimum 10 methods total).
8. Constructors (minimum two constructors and usage of reserved keyword this).
9. Mathematical algorithm / formula implementation (minimum 2, prebuilt static methods can be used to satisfy this requirement).
10. Files and I/O (Chapter 12).

the application I want to make is a password manager for multiple usernames and websites for a user to store and access and retrieve whenever they needed.