🚖 Cab Booking System (Spring Core - Annotation Based)

A simple Spring Core (Annotation-based) Java application that demonstrates Dependency Injection (DI), Bean Scopes, and Component Scanning using a cab booking scenario.

This project models a basic ride-booking system where a Driver is assigned to a ride and executes cab-driving operations.

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📌 Features

• Annotation-based Spring configuration (no XML)
• Demonstrates @Component, @Autowired, and @Scope
• Shows Singleton Bean Scope behavior
• Clean separation of configuration and business logic
• Simple and beginner-friendly structure

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🛠️ Tech Stack

• Java
• Spring Framework (Core)
• Maven (optional, if you add dependencies)

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📂 Project Structure

com.nit
│
├── config
│   └── AppConfig.java
│
├── main
│   └── TestApp.java
│
└── sbeans
    ├── Driver.java
    └── RideBooking.java

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⚙️ Configuration

AppConfig.java

• Enables component scanning for Spring Beans

@Configuration
@ComponentScan(basePackages="com.nit.sbeans")
public class AppConfig {
}

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🚗 Core Components

Driver.java

• Represents a cab driver
• Configured as a Singleton Bean

@Component
@Scope("singleton")
public class Driver {
    private String rideId;
    private String driverName;
    private String cabNumber;

    public void setDriver(String rideId, String driverName, String cabNumber) {
        this.rideId = rideId;
        this.driverName = driverName;
        this.cabNumber = cabNumber;
    }

    public void driveCab() {
        System.out.println("Your Cab Is On The Way....");
        System.out.println("Your Ride Id: "+rideId);
        System.out.println("Your Driver Name: "+driverName);
        System.out.println("Your Cab Number: "+cabNumber);
    }
}

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RideBooking.java

• Handles ride booking logic
• Uses Dependency Injection (@Autowired) to inject Driver

@Component
public class RideBooking {
    private String rideId;
    private String pickupLocation;

    @Autowired
    private Driver driver;

    public void setRideBooking(String rideId, String pickupLocation) {
        this.rideId = rideId;
        this.pickupLocation = pickupLocation;
    }

    public void bookRide() {
        System.out.println("===Your Ride Is Booked===");
        System.out.println("Your Ride ID: "+rideId);
        System.out.println("Your pickup location: "+pickupLocation);
        driver.driveCab();
    }
}

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▶️ Main Class

TestApp.java

• Bootstraps Spring Container
• Retrieves multiple Driver beans
• Demonstrates Singleton Scope (same object instance)

public class TestApp {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext ctx =
            new AnnotationConfigApplicationContext(AppConfig.class);

        Driver driver1 = ctx.getBean(Driver.class);
        Driver driver2 = ctx.getBean(Driver.class);
        Driver driver3 = ctx.getBean(Driver.class);

        driver1.setDriver("D101","Raj","UP202");
        driver2.setDriver("D202","Rahul","UP404");
        driver3.setDriver("D303","Ramesh","UP808");

        driver1.driveCab();
        driver2.driveCab();
        driver3.driveCab();

        System.out.println("Driver 1 hash code: "+driver1.hashCode());
        System.out.println("Driver 2 hash code: "+driver2.hashCode());
        System.out.println("Driver 3 hash code: "+driver3.hashCode());
    }
}

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🧠 Key Concepts Demonstrated

1. Dependency Injection

Spring automatically injects the Driver into RideBooking using @Autowired.

2. Component Scanning

Spring scans com.nit.sbeans package to detect beans using:

@ComponentScan(basePackages="com.nit.sbeans")

3. Bean Scope (Singleton)

Even though multiple beans are requested:

ctx.getBean(Driver.class);

➡️ All references point to the same object instance

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🧪 Sample Output

Your Cab Is On The Way....
Your Ride Id: D303
Your Driver Name: Ramesh
Your Cab Number: UP808

Driver 1 hash code: 12345678
Driver 2 hash code: 12345678
Driver 3 hash code: 12345678

👉 Notice all hash codes are identical → confirms Singleton scope.

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🚀 How to Run

1. Clone the repository
2. Open in any Java IDE (IntelliJ / Eclipse)
3. Add Spring dependencies if not already included
4. Run TestApp.java

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📌 Future Improvements

• Add Prototype scope example
• Introduce interfaces for loose coupling
• Add Spring Boot version
• Integrate database for real ride storage

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🤝 Contributing

Pull requests are welcome. Feel free to improve or extend the project.

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📄 License

This project is open-source and free to use for learning purposes.

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💡 Author

Developed as a learning project for understanding Spring Core fundamentals.

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