(JAVA) Create a class hierarchy to represent the different types of employees in an office who have the following job titles: manager, assistant, salesperson. Write an abstract base class called Employee that declares an abstract method: signature double calculateSalary() This class must also define the following attributes: name (String type), enrollment (String type) and base_salary (double type). Use encapsulation and provide a constructor that receives the corresponding values ​​to be stored in the respective attributes. This abstract class must be extended by the other classes representing the types of employees, so the classes Manager, Assistant and Salesperson must be written. In each class you must override the method calculateSalario so that the salary calculation is done like this: The manager receives twice the base_salary, the assistant receives the base_salary and the salesperson receives the base_salary plus a commission defined in the constructor of his class. Create a…

(The Person, Student, Employee, Faculty, and Staff classes) Design a class named Person and its two subclasses named Student and Employee. Make Faculty and Staff subclasses of Employee. A person has a name, address, phone number, and e-mail address. A student has a class status (freshman, sophomore, junior, or senior). Define the status as a constant. An employee has an office, salary, and date hired. Use the MyDate class defined in Programming Exercise 10.14 – see the textbook - to create an object for date hired. A faculty member has office hours and a rank. A staff member has a title. Override the toString method in each class to display the class name and the person's name. Draw the UML diagram for the classes and implement them. Write a test program that creates a Person, Student, Employee, Faculty, and Staff, and invokes their toString() methods.

(Inheriting Interface vs. Inheriting Implementation) A derived class can inherit “interface” or “implementation” from a base class. How do inheritance hierarchies designed for inheriting interface differ from those designed for inheriting implementation?

(Account class)Create an Account class that a bank might use to represent customers’ bank accounts. Include a data member of type int to represent the account balance. Provide a constructor that receives an initial balance and uses it to initialize the data member. The constructor should validate the initial balance to ensure that it’s greater than or equal to 0. If not, set the balance to 0 and display an error message indicating that the initial balance was invalid. Provide three member functions. Member function credit should add an amount to the current balance. Member function debit should withdraw money from the Account and ensure that the debit amount does not exceed the Account’s balance. If it does, the balance should be left unchanged, and the function should print a message indicating "Debit amount exceeded account balance." Member function get_Balance should return the current balance. Create a program that creates two Account objects and tests the member functions of class…

(Default Constructor) What’s a default constructor? How are an object’s data members initialized if a class has only an implicitly defined default constructor?

(Person Class) Design a class named Person that contains: o name, gender, and personCase as a private attribute o Non-default constructor that specifies name and gender o toString method that returns person data o personCase () method with no implementation (Student Class) Design a class named Student which is a child of Person that contains: o studentID as a private attribute o Nondefault constructor that specifies the name, gender, and studentID o toString method that returns student data o Implement personCase () that assigns "Not Studying" to personCase if studentID equals 0, “Studying" in case studentID greater than 0, and "Not a student" in case studentID less than 0. (Employee Class) Design a class named Employee which is a child of Person that contains: o employeelD as a private attribute o Non-default constructor that specifies the name, gender, and employeelD o toString method that returns employee data o Implement personCase () that assign “Technical" to personCase if…

(Composition as an Alternative to Inheritance) Many programs written with inheritancecould be written with composition instead, and vice versa. Rewrite class BasePlusCommissionEmployee of the CommissionEmployee–BasePlusCommissionEmployee hierarchy to use compositionrather than inheritance. After you do this, assess the relative merits of the two approaches for designing classes CommissionEmployee and BasePlusCommissionEmployee, as well as for object-oriented programs in general. Which approach is more natural? Why?

(JAVA) The use case description for the View Exam Grades use case is described below. Determineclasses that are needed to implement the use case. Also, define each class's attributes andmethods. Represent class and its attributes and methods using the UML class notation.Use case name: View Exam Grades.Summary: The student looks at his/her exam grade of CS2365 OOP or CS3365 SoftwareEngineering.Actor: StudentPrecondition: None.Main sequence:1. The student enters the student ID and password into the system.2. The system checks if the student ID and password are valid.3. The system displays the course numbers (e.g., CS2365 and CS3365) if the ID andpassword are valid.4. The customer chooses only a course to view the grade.5. The system displays the course grade to the student.Alternative sequence:Step 3: If the student's ID and password are invalid, the system displays an error messageand asks to enter another ID and password into the system. If the ID and password arevalid, the system…

(The Account class)       Account   -id: int -balance: double -annualInterestRate : double -dateCreated : Date   +Account( ) +Account(someId : int, someBalance : double) +getId() : int +setId(newId : int) : void +getBalance() : double +setBalance(newBalance : double) : void +getAnnualInterestRate( ) : double +setAnnualInterestRate(newRate : double) : void +getDateCreated( ) : Date +getMonthlyInterestRate( ) : double +getMonthlyInterest( ) : double +withdraw(amt : double) : void +deposit(amt : double) : void         Design a class named Account that contains: ■ A private int data field named id for the account (default 0). ■ A private double data field named balance for the account (default 0). ■ A private double data field named annualInterestRate that stores the current interest rate (default 0). Assume all accounts have the same interest rate.  Make it static. ■ A private Date data field named dateCreated that stores the date when the account was created.  (private Date dateCreated)…