elevator-system.md

Designing an Elevator System

This article explores the design and implementation of an Elevator System using object-oriented principles in Java, focusing on functionality, scalability, and user interaction.

System Requirements

The Elevator System is designed to:

1. Handle Multiple Requests: Manage requests from different floors efficiently.
2. Optimize Elevator Movement: Allocate elevators based on requests to improve efficiency.
3. Track Elevator Status: Monitor the state and position of each elevator.
4. Incorporate Safety Features: Ensure key safety mechanisms are in place.

Core Use Cases

1. Requesting an Elevator: Users can call elevators to their current floor.
2. Transporting Passengers: Elevators carry passengers to their desired floors.
3. Managing Idle Elevators: Efficiently allocate available elevators.

Key Classes:

• ElevatorSystem: Manages multiple elevators.
• Elevator: Represents an individual elevator.
• ElevatorControlPanel: Interface for users to interact with an elevator.

Java Implementation

Elevator Class

This class represents an individual elevator.

public class Elevator {
    private int currentFloor;
    private ElevatorState state;

    public Elevator() {
        this.currentFloor = 0; // Starting at ground floor
        this.state = ElevatorState.IDLE;
    }

    public void moveToFloor(int floor) {
        // Simulate elevator movement
        this.currentFloor = floor;
        this.state = ElevatorState.MOVING;
        // Assume elevator reaches the floor instantly
        this.state = ElevatorState.IDLE;
    }

    // Getters and setters...
}

ElevatorSystem Class

import java.util.*;

public class ElevatorSystem {
    private List<Elevator> elevators;

    public ElevatorSystem(int numberOfElevators) {
        elevators = new ArrayList<>();
        for (int i = 0; i < numberOfElevators; i++) {
            elevators.add(new Elevator());
        }
    }

    public void requestElevator(int floor) {
        Elevator closestElevator = findClosestElevator(floor);
        if (closestElevator != null) {
            closestElevator.moveToFloor(floor);
        }
    }

    private Elevator findClosestElevator(int floor) {
        Elevator closest = null;
        int minDistance = Integer.MAX_VALUE;
        for (Elevator elevator : elevators) {
            int distance = Math.abs(elevator.getCurrentFloor() - floor);
            if (distance < minDistance && elevator.getState() == ElevatorState.IDLE) {
                closest = elevator;
                minDistance = distance;
            }
        }
        return closest;
    }

    // Other necessary methods...
}

ElevatorControlPanel Class

public class ElevatorControlPanel {
    private Elevator elevator;

    public ElevatorControlPanel(Elevator elevator) {
        this.elevator = elevator;
    }

    public void goToFloor(int floor) {
        elevator.moveToFloor(floor);
    }

    // Other necessary methods...
}