This lab will use the concept of a doubly-linked list to simulate part of an air traffic control system. The program will manage the arrival and departure of flights into and out of your airspace.

The job of air traffic controller involves taking responsibility for all of the aircraft in a specific area of the airspace. The airspace for this problem will be a piece of the traffic corridor between the cities of Buffalo and Boston, Ma. Other controllers will have responsibility for the area to the east, west, north and south of you but your area will be under your exclusive control.

The program will accept certain commands from you and will display certain information to you in response. The commands and their responses will be as follows:

Command: “Entering” – This command will signal that an aircraft has entered your airspace. You will be able to specify

The ID            int     of an aircraft

The altitude   int     thousands of feet

The speed       int     miles per hour

The name       String (ex: “U566”)

Response: one aircraft will be added to your problem

Command: “Leaving” – you will give the aircraft name

Response: it will be removed from your problem

Command: “Show” – you will give the aircraft name

Response: all information for that aircraft will be displayed

Command: “Display” –

Response: all aircraft in your problem will be displayed in a list

Implementation:

You will create a doubly-linked list in Java. You will implement an “aircraft” class which will take the place of the node class which was discussed. Objects of this aircraft class will be linked together in a list, as they are entered into the problem. When the “Display” command is entered, all the aircraft currently on the list will be displayed to the user.

Remember:

Use object reference variables for links between nodes

Implement two classes

linked list class which will be used by main to manipulate objects of the aircraft class

an aircraft class whose objects will contain aircraft information.

The main program should be the place where all of the “conversation” with the user takes place. This means that;

The linked list object will be able to return a single aircraft object in response to the “Show” command and will return an array of aircraft objects in response to the “Display” command.

The aircraft class should have a method that returns a String, suitable for displaying all of its information (used in the “Show” command) and another method that returns its name (used in the “Display” command). This will prevent the main program from having to know the details of the data inside the aircraft class.

There will be NO keyboard or display accessing in the aircraft class nor in the linked list class

Outline of classes

Main

          Create linked list object

          Loop while cmd not “quit”

                   Enter

                             Get AC info from user

                             Add an AC to list

                   Leave

          Get AC name from user

                             Delete AC from list

                   Display

              Get AC count from list

              Loop from 1 to count

                        Show each AC

              Display all existing AC in order of altitude

     Show

              Get AC name from user

              Search list for name

              Show AC found

          When quitting, tell list to delete all remaining AC (if any).

Linked List

          Get AC count

          Add an AC

          Delete an AC

          Show AC by number

          Search for AC by name and return the number

          Delete all AC

Aircraft

          Get name

          Set name

          Set type

          Set altitude

          Set speed

Testing:

In order to save a lot of typing, you may use single character commands (Ex: ‘e’ for “entering”, ‘l’ for “leaving” etc.).

You should be able to

“entering” the first aircraft

“entering” the second aircraft

“entering” the third aircraft

“display” all three, in altitude-order

“show” the first

“show” the third

“leaving” the second

“show” the second (present an appropriate error message)

“display” both remaining

“leaving” the third

“display” the remaining one

“leaving’ the first

“display” the empty list