🚀 Spring Core – Prototype Scope & Dependency Injection Demo

This project demonstrates core Spring Framework (Spring Core / IoC) concepts such as Annotation-based configuration, Dependency Injection, and Bean Scopes (singleton vs prototype).

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📌 Project Overview

This is a simple Java application that simulates an order delivery system where:

• A Customer places an order
• A DeliveryService processes and delivers the order

The main goal is to understand how Spring manages object creation and dependency injection using annotations.

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🧠 Key Concepts Covered

• ✅ Annotation-based configuration (@Configuration, @ComponentScan)

• ✅ Dependency Injection using @Autowired

• ✅ Bean Scopes:

  • Singleton (default scope)
  • Prototype

• ✅ Spring IoC Container usage

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📂 Project Structure

com.nit
│
├── config
│   └── AppConfig.java
│
├── main
│   └── TestApp.java
│
└── sbeans
    ├── Customer.java
    └── DeliveryService.java

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⚙️ Configuration

Spring configuration is done using Java annotations:

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

This tells Spring to scan the specified package for components.

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🔗 Dependency Injection

The Customer class depends on DeliveryService, which is injected automatically:

@Autowired
private DeliveryService deliveryService;

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🔁 Bean Scope Behavior

🔹 Customer (Prototype Scope)

@Scope("prototype")

• A new object is created every time the bean is requested from the container.

🔹 DeliveryService (Singleton Scope - Default)

• Only one shared object exists throughout the application.

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▶️ Application Flow

1. Spring container is initialized using AnnotationConfigApplicationContext
2. Two DeliveryService beans are requested → SAME instance
3. Two Customer beans are requested → DIFFERENT instances
4. Each customer places an order
5. Output confirms scope behavior using hashcodes

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▶️ How to Run

✅ Prerequisites

• Java 8 or higher
• IDE (Eclipse / IntelliJ / VS Code)

▶️ Steps

1. Clone the repository
2. Open in your IDE
3. Run TestApp.java

OR via terminal:

javac *.java
java com.nit.main.TestApp

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📊 Sample Output

====Sevice Details===
Order is placing...
Service Name: Swiggy Delivery
Total no of orders : 2
Order is Delivered
-----Customer Detail----
Customer ID: CUS101
Customer Name: Raj

====Sevice Details===
Order is placing...
Service Name: Swiggy Delivery
Total no of orders : 2
Order is Delivered
-----Customer Detail----
Customer ID: CUS103
Customer Name: Rahul

Hash code of customer1: 12345678
Hash code of customer2: 87654321

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🔍 Key Observations

• ✔ Customer beans have different hashcodes → Prototype scope works
• ✔ DeliveryService behaves like a shared object → Singleton scope
• ✔ Even multiple calls to getBean() return the same DeliveryService instance

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💡 Learning Outcome

By completing this project, you will understand:

• How Spring IoC container manages beans
• Difference between Singleton and Prototype scope
• Real-world usage of Dependency Injection
• Annotation-based configuration in Spring

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🛠️ Tech Stack

• Java
• Spring Core (IoC Container)
• Annotation-based configuration

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📬 Author

This project is created for learning and practicing Spring Core fundamentals.

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⭐ Feel free to fork, modify, and experiment with this project!