In Java I need a code that its purpose of these services is to add, update, and delete contact objects within the application.

The contact service uses in$-$memory data structures to support storing contacts $($no database required$).$ In addition, there is no user interface for this milestone. You will verify the contact service through JUnit tests. The contact service contains a contact object along with the contact service. The requirements are outlined below.

Contact Class Requirements

The contact object shall have a required unique contact ID string that cannot be longer than $10$ characters. The contact ID shall not be null and shall not be updatable.

The contact object shall have a required firstName String field that cannot be longer than $10$ characters. The firstName field shall not be null.

The contact object shall have a required lastName String field that cannot be longer than $10$ characters. The lastName field shall not be null.

The contact object shall have a required phone String field that must be exactly $10$ digits. The phone field shall not be null.

The contact object shall have a required address field that must be no longer than $30$ characters. The address field shall not be null.

Contact Service Requirements

The contact service shall be able to add contacts with a unique ID$.$

The contact service shall be able to delete contacts per contact ID$.$

The contact service shall be able to update contact fields per contact ID$.$ The following fields are updatable:

firstName

lastName

Number

Address

To complete this assignment must contain the following deliverables:

Contact.java

ContactService.java

ContactTest.java

ContactServiceTest.java