ePJ2 — JavaCity Fleet Operations Dashboard

ePJ2 is an electric vehicle rental simulation system for the fictional city of JavaCity.
It manages a fleet of cars, bikes, and scooters across a real-time 20×20 city grid, calculates rental fares, tracks malfunctions, and produces financial reports — all through a dark tactical HUD-style GUI built with Java Swing.

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🖥️ Screenshots

Main Dashboard — Idle

The dashboard on startup, before a simulation is launched.

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Simulation Running

Vehicles moving across the city grid in real time. Green = Scooter, Red = Car, Yellow = Bike.
The SIM LOG panel on the right streams dispatch events live.

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After Simulation — Monitors Updated

Sales, Salary, and Repair monitors filled with results after the simulation completes.

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🚀 How to Run (Eclipse IDE)

Recommended environment: Eclipse IDE for Java Developers

Step 1 — Import the project

1. Open Eclipse.
2. Go to File → Import → Existing Projects into Workspace.
3. Select the root folder of the repository and click Finish.

Step 2 — Ensure the CSV data files are in the project root

Place the following files directly in the project root (same level as src/):

PJ2 - projektni zadatak 2024 - Prevozna sredstva.csv    ← vehicle data
PJ2 - projektni zadatak 2024 - Iznajmljivanja.csv        ← rental data

Step 3 — Run the application

1. In the Package Explorer, expand src → gui.
2. Right-click MainWindow.java.
3. Select Run As → Java Application.
4. The dashboard window will open.

Step 4 — Start the simulation

Click the ▶ START SIMULATION button in the bottom-right corner of the dashboard.
The simulation will:

• Load all vehicles and rentals from the CSV files.
• Dispatch each vehicle as a separate thread.
• Animate vehicle movement live on the city map.
• Stream log events to the SIM LOG panel.
• Fill the SALES, SALARY, and REPAIRS monitors when done.
• Open a popup showing the most loss-making vehicle type.

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📋 Project Overview

The system tracks three types of electric vehicles:

Type	Battery	Map Colour
Car	300 units	🔴 Red
Bike	200 units	🟡 Yellow
Scooter	100 units	🟢 Green

Each vehicle is a Java thread — it moves step-by-step across the 20×20 grid, drains its battery per step, and generates a Bill for its passenger on arrival.

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🛠️ Features

1 — Vehicle Management

• Three vehicle subclasses: Car, Bike, Scooter (extend abstract Vehicle extends Thread).
• VehicleType enum replaces all raw type strings ("automobil", "bicikl", "trotinet").
• Each vehicle exposes a getMapColor() method — the map panel uses polymorphism to colour cells with zero instanceof checks.
• Battery charges and discharges per movement step; two bugs in the original Battery class were fixed during refactoring.

2 — Rental System

• Rentals are loaded from a CSV file, validated, deduplicated, and sorted chronologically.
• Fare calculation accounts for: base unit price per vehicle type, wide/narrow city zone multiplier, every-10th-rental promotional discount, and malfunction waiver.
• Passengers are randomly assigned as Local (national ID) or Stranger (passport).
• A Bill is generated and attached to each passenger at trip end.

3 — Real-Time Simulation

• Each vehicle runs on its own Thread.
• The city grid is a 20×20 array of Object cells protected by per-cell ReentrantLocks.
• The map repaints at ~30 fps via a Swing Timer.
• Vehicle movement is logged live in the SIM LOG panel.

4 — Financial Reports (Monitors)

Three monitors update automatically after the simulation ends:

Monitor	Tracks
SALES	Number of rentals per vehicle type
SALARY	Total revenue, discount revenue, promotion revenue
REPAIRS	Repair costs per vehicle type (7% / 4% / 2% of purchase price)

The most loss-making vehicle type is serialized to Reports/MostLossMakingVehicles.ser and deserialized into a popup window.

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🎨 GUI Design

The interface follows a dark tactical HUD aesthetic — think mission control for a smart city.

Element	Description
Title bar	App name in electric cyan + live HH:mm:ss clock
SALES / SALARY / REPAIRS panels	Left column, stacked flush, each with a titled header strip
CITY MAP	Centre panel — dark grid, glowing vehicle cells, dashed zone boundary
SIM LOG	Right panel — live scrolling dispatch log
Bottom bar	Vehicle legend, status text, glowing START button

All design tokens (colours, fonts) live in AppTheme.java. Changing one value propagates everywhere.

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📁 Project Structure

ePJ2/
│
├── src/
│   ├── battery/          Battery, BatteryException
│   ├── bill/             Bill
│   ├── data/             VehicleDataLoader, RentalDataLoader
│   ├── gui/              MainWindow, MapPanel, AppTheme, GlowButton,
│   │                     LossMakingVehiclesWindow
│   ├── javacitymap/      JavaCityMap, JavaCityMapException
│   ├── malfunction/      Malfunction
│   ├── model/            Vehicle (abstract), Car, Bike, Scooter, VehicleType
│   ├── monitor/          RentalSalesMonitor, RentalSalaryMonitor,
│   │                     RentalRepairCostsMonitor
│   ├── passenger/        Passenger (abstract), Local, Stranger
│   ├── rental/           Rental
│   └── utility/          ConfigFileCreator, ConfigFileReader,
│                         Serializer, Deserializer, RandomStringGenerator
│
├── Reports/              Serialized binary output (auto-created at runtime)
├── config.properties     Auto-generated pricing config
├── PJ2 - projektni zadatak 2024 - Prevozna sredstva.csv
├── PJ2 - projektni zadatak 2024 - Iznajmljivanja.csv
└── README.md

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🔧 Key Refactoring Changes

This project was significantly refactored from the original submission. Notable improvements:

• VehicleType enum — eliminates all raw Bosnian string literals scattered across six files.
• Bug fix: Battery.charge() — original code always added 100 instead of the amount argument.
• Bug fix: Battery.setChargeLevel() — original guard condition 0 < status && status >= 100 was logically impossible (nothing could satisfy it).
• Thread-safe monitors — AtomicLong / DoubleAdder replace plain static double fields.
• getMapColor() polymorphism — MapPanel has no instanceof chain; each vehicle subclass declares its own colour.
• Billing extracted — fare calculation moved out of Vehicle.run() into a dedicated generateBill() method.
• Deleted dead code — proba/ package (commented-out scratch tests) and duplicate user/ package removed entirely.
• All identifiers translated to English — no Bosnian/Serbian variable or method names remain in the codebase.

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📑 Configuration

config.properties is auto-created on first run by ConfigFileCreator. Default values:

CAR_UNIT_PRICE     = 0.05
BIKE_UNIT_PRICE    = 0.02
SCOOTER_UNIT_PRICE = 0.01
DISTANCE_WIDE      = 1.5
DISTANCE_NARROW    = 1.0
DISCOUNT           = 0.1
DISCOUNT_PROM      = 0.05

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💡 Best Practices Applied

• Full JavaDoc on all public classes and methods.
• Packages for every logical layer.
• Single Responsibility — data loading, simulation, billing, and monitoring are separate concerns.
• ReentrantLock per grid cell for fine-grained thread safety.
• Collections.synchronizedList for shared vehicle lists in monitors.

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🛡️ License

Developed as part of the Programski jezici 2 course at
Elektrotehnički fakultet, Banja Luka.

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👥 Contributors

• Andrej Trožić — Student, Elektrotehnički fakultet Banja Luka