Microservices Quiz System

📌 Overview

This project is built using Spring Boot + Spring Cloud and follows the Microservices Architecture pattern.
It consists of multiple independent services communicating through Eureka Server and API Gateway.

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🛠️ Technologies Used

• Java 21
• Spring Boot 3.5.5
• Spring Cloud Gateway
• Netflix Eureka (Service Discovery)
• PostgreSQL (Database for Quiz Service)
• Maven

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🏗️ Architecture

                  +--------------------+
                  |   API Gateway      |
                  |  (port: 8765)      |
                  +---------+----------+
                            |
        -----------------------------------------------
        |                                             |
+---------------+                            +-----------------+
| QuestionService|                            |   QuizService   |
| (port: 8081)   |                            |  (port: 8090)   |
+----------------+                            +-----------------+
          |                                          |
          |                                          |
    +-------------+                           +--------------+
 |questiondb(PostgreSQL)|                    |quizdb(PostgreSQL)| 
    +-------------+                           +--------------+

                  +--------------------+
                  |   Eureka Server    |
                  |  (Service Registry)|
                  +--------------------+

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📂 Services

1️⃣ API Gateway (Port 8765)

• Entry point for all client requests.
• Routes requests to the appropriate microservices using Eureka Service Discovery.
• Auto routing enabled via Discovery Locator.
• Example request:

  http://localhost:8765/quiz-service/quiz/get/3
  

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2️⃣ Eureka Server

• Service registry for all microservices.
• Displays the registered instances and their status via UI.

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3️⃣ Question Service (Port 8081)

• Manages questions.
• Endpoints:

  GET  /question/allQuestions
  GET  /question/category/{category}
  POST /question/add
  GET /question/generate
  POST /question/getQuestions
  POST /question/getScore
  

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4️⃣ Quiz Service (Port 8090)

• Responsible for quiz creation, retrieval, and submission.
• Connected to PostgreSQL database.
• Endpoints:

  POST /quiz/create
  GET  /quiz/get/{id}
  POST /quiz/submit/{id}
  

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📌 Postman Examples

🔹 1. Create a new Quiz

POST http://localhost:8765/quiz-service/quiz/create

{
  "categoryName": "java",
  "numQuestions": 5,
  "title": "Java Basics Quiz"
}

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🔹 2. Get Quiz Questions

GET http://localhost:8765/quiz-service/quiz/get/1

Response Example:

[
  {
    "id": 10,
    "questionTitle": "What is JVM?",
    "option1": "Java Virtual Machine",
    "option2": "Java Vendor Machine",
    "option3": "Just Virtual Machine",
    "option4": "None",
    "rightAnswer": null
  },
  {
    "id": 11,
    "questionTitle": "Which keyword is used to inherit a class?",
    "option1": "implement",
    "option2": "this",
    "option3": "extends",
    "option4": "super",
    "rightAnswer": null
  }
]

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🔹 3. Submit Quiz Answers

POST http://localhost:8765/quiz-service/quiz/submit/1

[
  { "id": 10, "response": "Java Virtual Machine" },
  { "id": 11, "response": "extends" }
]

Response Example:

2

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🔹 4. Get Questions by Category

GET http://localhost:8765/question-service/question/category/java

Response Example:

[
  {
    "id": 1,
    "questionTitle": "What is Polymorphism?",
    "option1": "Overloading & Overriding",
    "option2": "Encapsulation",
    "option3": "Inheritance",
    "option4": "Abstraction",
    "rightAnswer": "Overloading & Overriding",
    "difficultyLevel": "Medium",
    "category": "java"
  }
]