Java - TP4

Rated TP - Elevator Game

Instructions

• Groups of 1 or 2 students
  • Inter-group plagiarism will be severely punished
• Due Date: Friday 10 April at 5pm
  • 1 point deducted for each half-hour delay
• In a README file, indicate:
  • your full names
  • list the questions that have been completed or not. Feel free to add comments
• Zip folder tp4 and load it on Moodle
  • Don’t include target folder

Your code must be functional, with no compilation or runtime errors.

Don’t forget to include the javadoc and to comment your code if necessary.

Important

• Everything you need is in the course and the practical exercises
• You are permitted to conduct internet searches to find information and documentation
• The use of any LLM is strictly prohibited during this exam
  • As Olivier R. so rightly says: LLMs are good servants, but bad masters
  • They can be useful tools, but they must not replace your own comprehension and programming skills

If you are caught using an LLM, it will be considered cheating and you will receive a zero.

Launch service VSCode Java

• Restart the service from the last lab or Launch a new service VScode-Java

Update your repository

Perhaps the repository used as a template has been updated since the last practical session.

• Follow the commands given in Lab 2 to update your repository

Caution

Service interruptions are possible. To prevent data loss, back up your code regularly with Git.

After each part, create a commit and push your code to the remote repository.

When you’ve finished

• Save your work using git
• Delete your service

1 Subject

In this project, you will model and simulate the operation of elevators in a small hotel. The goal is to design a simple object-oriented system where people appear on different floors, request an elevator, travel to their destination, and exit when they arrive.

This topic is inspired by Elevator Saga.

2 Questions

2.1 Simulation setup

The Main class is used to run the simulation. Here, you define the hotel, its floors, and the elevators, then run the simulation.

Each step, people may arrive on each floor to call an elevator.

• Set the probability that a person will arrive on the ground floor at each step to 0.65

It’s annoying to have to enter one by one elevators and floors. It would be easier just to specify the number you want.

• Make sure that the number of floors and elevators can be easily configured

In the Person class, a value depends on the number of floors.

• Ensure that this value is retrieved from elsewhere and do not hard-code it

In the Elevator class:

• Add the isFull() method
• Use it in another method of the same class

2.2 Request an elevator

When someone reaches a floor, they press the button to call an elevator.

For now, all these calls are sent to the first elevator.

• Implement new rules:
  • if an elevator is already on its way to that floor, do nothing
  • otherwise, find the least busy elevator and add the floor to the end of its destinations list
• Update the JavaDoc (to be done for each question if necessary)

2.3 Target Floor

On each floor, people may arrive randomly.

You may have noticed in the simulation that some people arrive on floor n and want to go to floor n.

Perhaps, like children, they find it fun to take the elevator, but to make the simulation more realistic:

• Ensure that people choose a target floor at random from among the other floors in the hotel.

2.4 Unit test

Let’s write some unit tests with JUnit (no need for Mockito).

• Explain why it is complicated to test the isFull() method of the Elevator class.
• Add an appropriate method and code unit tests for method isFull()
• Create an run unit tests for method Elevator.addDestination()

2.5 Crazy Elevator

It wasn’t specified yet, but we are in a haunted hotel where the elevators sometimes go crazy.

• Create a class CrazyElevator

NoteBehaviour

At each step, a crazy elevator can, with equal probability:

• remain stationary
• skip its next destination and go directly to the next one
• go to the next floor as a normal elevator

• Update the appropriate method

Half the time, a crazyElevator may decide not to unload its passengers.

• Update the appropriate method

If it is full, it will send all its passengers into another dimension.

• Update the appropriate method
• Add a crazy elevator in the hotel

2.6 Elevator Direction

We would like to know at all times whether the elevator is going up, down or is idle (inactive).

• Add attribute direction to each Elevator and each Person
  • choose the appropriate type
• Find the appropriate method for updating the direction
• Bonus: in class Hotel, update the display to show an arrow symbol next to Elevator.

+-------+--------------------------+--------------------------+----------------------+
| Floor | Elevator1 ↑              | Elevator2 ↓              | waitingPersons       |
+-------+--------------------------+--------------------------+----------------------+
|     3 |                          |                          |                      |
|     2 |                          |                          | g3                   |
|     1 |                          | [        ]               |                      |
|     0 | [e2      ]               |                          | f2                   |
+-------+--------------------------+--------------------------+----------------------+