You will implement $2$ different patterns.$$

First design pattern :

Observer Pattern

We would like to keep track of updates in the employee list. Whenever a new employee is added, or their role$/$department is changed, an update notification should be sent to all observers $($e$.$g$.,$ HR or department managers$).$ You will create an observer mechanism to handle these updates.

Create an ObservableEmployeeList class that maintains the list of employees and notifies the observers when changes are made.

Implement the Observer interface and concrete observers such as HRDepartmentObserver and ManagerObserver.

The ObservableEmployeeList will notify observers of events such as employee addition or updates in role$/$department$.$

HINT

ObservableEmployeeList employeeList $=$ new ObservableEmployeeList$()$;

employeeList.addObserver$($new HRDepartmentObserver$())$;

employeeList.addObserver$($new ManagerObserver$())$;

employeeList.addEmployee$($new Employee$(...))$; $//$ This triggers a notification to all observers.

Second Design Pattern

Adapter Pattern

My favorite pattern to go with is the adapter pattern. I want you to integrate a new third party system$$

for salary calculation that doesn't follow your existing interface. To make it work within your existing application, you will implement the Adapter Pattern.

You will create an ExternalSalaryCalculator class $($assume this is the third$-$party system you need to adapt$).$

Implement an ExternalSalaryAdapter class that adapts this third$-$party class to work with your existing Compensable interface.

The ExternalSalaryAdapter should implement the calculateTotalCompensation$()$ method to adapt the third$-$party logic and make it compatible with your current system.

HINT

ExternalSalaryCalculator externalCalculator $=$ new ExternalSalaryCalculator$()$;

System.out.printlnAdapter $=$ new ExternalSalaryAdapter$($externalCalculator$)$;

System.out.println$("$Total Compensation: $"+$ salaryAdapter.calculateTotalCompensation$())$;

Submission:

Upload the following files:

person.java

Employee.java

Manager.java

BonusStrategy.java

ReportGenerator.java

EmployeeFactory.java

ObservableEmployeeList.java

HRDepartmentObserver.java

ManagerObserver.java

ExternalSalaryAdapter.java

To achieve bonus points$$

Add another $($any$)$ designer patternAdd another observer pattern