System using an AdminInterface

    Q1. Based on the following description, create a domain model first, and then draw a sequence diagram for the job application scenario. Also, define two operation contracts: (20 pts) You are designing an employment application server. The server supports three types of users: Applicants, Staff, and Admin. The server records applicants’ personal info, job type, and date in a database. Staff can access data but cannot manage users or create jobs. Admin is able to create jobs and manage users. A typical application process is: - Admin creates a job on the system using an AdminInterface. - Job is posted on the employment website. - Applicant fills out an online form to enter personal info, job type. The information is saved into the database. - Staff reviews the application through a StaffInterface and sends it to the employing company. - If the company accepts the application, staff e-mails the acceptance letter to applicant and Admin deletes the job. - If the company rejects the application, staff e-mails the rejection letter to applicant. - What does “program to an interface not an implementation” mean? Explain it using an example that you created. (10 pts)