Parking Lot System

A Java-based automated parking lot management system that provides an interactive command-line interface for managing parking operations. The system supports both interactive shell mode and file-based batch processing.

Overview

This project implements a parking lot ticketing system that allows customers to park their cars without human intervention. The system automatically allocates the nearest available parking slot, issues tickets, and provides various query capabilities for managing and tracking parked vehicles.

Features

• Automated Slot Allocation: Automatically assigns the nearest available parking slot
• Ticket Management: Issues and tracks parking tickets
• Interactive CLI: Command-line interface for real-time operations
• Batch Processing: File-based input for automated operations
• Query Capabilities: Search by registration number, color, and slot number
• Status Monitoring: View current parking lot status

Project Description

This is a boilerplate code for the java based implementation of parking lot problem statement described below.

This code will be given to a candidate coming for an onsite interview so that they can take the implementation forward.

Requirements

The project is built using Java 1.8. It uses Maven as the build system.

1. Java - 1.8.x
2. Maven - 3.x.x

Quick Start

1. Clone the repository:

git clone https://github.com/Kakashi54321/ParkingLot_System.git
cd ParkingLot_System

2. Build the application:

cd application
mvn clean package

3. Run the application:

# Interactive mode
java -jar target/application.jar

# File input mode
java -jar target/application.jar file_input.txt

Building the application using maven

You can build and package the application in the form of a jar file using maven -

cd application
mvn clean package

The above command will produce a standalone jar file named goparking.jar in the GoParking/target directory.

Running tests

The mvn package command runs all the unit tests and also packages the application in the form of a jar file. If you just want to run the tests without packaging it, then you can use mvn test command.

cd application
mvn test

Running the application

You can run the jar file created by the mvn package command like so -

java -jar target/application.jar

Running the functional tests

./bin/run_functional_tests

The above command launches an interactive shell where you can type various parking lot commands and receive the output on the console.

The application can also take input commands from a file. You can pass multiple commands separated by a newline in the file like so -

java -jar target/goparking.jar file_input.txt

Problem Statement

I own a parking lot that can hold up to 'n' cars at any given point in time. Each slot is given a number starting at 1 increasing with increasing distance from the entry point in steps of one. I want to create an automated ticketing system that allows my customers to use my parking lot without human intervention.

When a car enters my parking lot, I want to have a ticket issued to the driver. The ticket issuing process includes us documenting the registration number (number plate) and the colour of the car and allocating an available parking slot to the car before actually handing over a ticket to the driver (we assume that our customers are nice enough to always park in the slots allocated to them). The customer should be allocated a parking slot which is nearest to the entry. At the exit the customer returns the ticket which then marks the slot they were using as being available.

Due to government regulation, the system should provide me with the ability to find out:

• Registration numbers of all cars of a particular colour.
• Slot number in which a car with a given registration number is parked.
• Slot numbers of all slots where a car of a particular colour is parked.

We interact with the system via a simple set of commands which produce a specific output. Please take a look at the example below, which includes all the commands you need to support - they're self explanatory. The system should allow input in two ways. Just to clarify, the same codebase should support both modes of input - we don't want two distinct submissions.

1. It should provide us with an interactive command prompt based shell where commands can be typed in.
2. It should accept a filename as a parameter at the command prompt and read the commands from that file.

Commands which have already been implemented

• create_parking_lot <numSlots> - Creates a parking lot with the specified number of slots
• park <registrationNumber> <color> - Parks a car and allocates the nearest available slot
• leave <slotNumber> - Frees up a parking slot
• status - Displays the current status of all occupied parking slots

Commands to implement

• registration_numbers_for_cars_with_colour <color> - Get all registration numbers of cars with a specific color
• slot_numbers_for_cars_with_colour <color> - Get all slot numbers where cars of a specific color are parked
• slot_number_for_registration_number <registrationNumber> - Get the slot number for a given registration number

Interactive mode test

$ create_parking_lot 6
Created a parking lot with 6 slots

$ park KA-01-HH-1234 White
Allocated slot number: 1

$ park KA-01-HH-9999 White
Allocated slot number: 2

$ park KA-01-BB-0001 Black
Allocated slot number: 3

$ park KA-01-HH-7777 Red
Allocated slot number: 4

$ park KA-01-HH-2701 Blue
Allocated slot number: 5

$ park KA-01-HH-3141 Black
Allocated slot number: 6

$ leave 4
Slot number 4 is free

$ status
Slot No.  Registration No Colour
1         KA-01-HH-1234   White
2         KA-01-HH-9999   White
3         KA-01-BB-0001   Black
5         KA-01-HH-2701   Blue
6         KA-01-HH-3141   Black

$ park KA-01-P-333 White
Allocated slot number: 4

$ park DL-12-AA-9999 White
Sorry, parking lot is full

$ registration_numbers_for_cars_with_colour White
KA-01-HH-1234, KA-01-HH-9999, KA-01-P-333

$ slot_numbers_for_cars_with_colour White
1, 2, 4

$ slot_number_for_registration_number KA-01-HH-3141
6

$ slot_number_for_registration_number MH-04-AY-1111
Not found

$ exit

Batch mode test

To run the code so it accepts input from a file:

$ bin/parking_lot file_inputs.txt
Input (contents of file):
create_parking_lot 6
park KA-01-HH-1234 White
park KA-01-HH-9999 White
park KA-01-BB-0001 Black
park KA-01-HH-7777 Red
park KA-01-HH-2701 Blue
park KA-01-HH-3141 Black
leave 4
status
park KA-01-P-333 White
park DL-12-AA-9999 White
registration_numbers_for_cars_with_colour White
slot_numbers_for_cars_with_colour White
slot_number_for_registration_number KA-01-HH-3141
slot_number_for_registration_number MH-04-AY-1111

Output:

Created a parking lot with 6 slots
Allocated slot number: 1
Allocated slot number: 2
Allocated slot number: 3
Allocated slot number: 4
Allocated slot number: 5
Allocated slot number: 6
Slot number 4 is free
Slot No.  Registration No
1         KA-01-HH-1234
2         KA-01-HH-9999
3         KA-01-BB-0001
5         KA-01-HH-2701
6         KA-01-HH-3141
Allocated slot number: 4
Sorry, parking lot is full
KA-01-HH-1234, KA-01-HH-9999, KA-01-P-333
1, 2, 4
6
Not found