Quora API

RESTful backend for a Q&A platform similar to Quora. This application handles user management, questions, answers, comments, and social interactions like following and liking.

Built with Java and Spring Boot.

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Table of Contents

• Features
• Tech Stack
• API Documentation
• Project Structure

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Features

• User Management: Register, update profiles, and view user details.
• Q&A Engine: Post questions, search by tag/text, and provide answers.
• Nested Comments: Comment on answers and reply to other comments.
• Social Interactions: Follow other users and "Like" content (Questions, Answers, Comments).
• Topics: Create and manage topics/tags for questions.

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Tech Stack

• Language: Java 17
• Framework: Spring Boot 3.5.10
• Build Tool: Gradle
• Database: MySQL
• Utilities: Project Lombok

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API Documentation

Version: 1.0.0
Base URL: /api/v1

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1. User Management

Base Path: /users

1.1 Register User

Register a new user in the system.

• Endpoint: POST /users

• Request Body:

  {
    "username": "johndoe",
    "email": "john@example.com",
    "bio": "Software Engineer and Tech Enthusiast"
  }
  

• Response (201 Created):

  {
    "id": "123e4567-e89b-12d3-a456-426614174000",
    "username": "johndoe",
    "email": "john@example.com",
    "bio": "Software Engineer and Tech Enthusiast",
    "questions": [],
    "answers": [],
    "comments": [],
    "followers": [],
    "follows": []
  }
  

1.2 Get All Users

Retrieve a list of all registered users.

• Endpoint: GET /users

• Response (200 OK): List<UserResponse>

1.3 Get User Info

Retrieve public profile information for a specific user.

• Endpoint: GET /users/{userId}

• Path Parameters: userId: UUID of the user

• Response (200 OK): UserResponse

1.4 Update User

Update profile details for an existing user.

• Endpoint: PUT /users/{userId}

• Request Body:

  {
    "username": "john_updated",
    "email": "john_new@example.com",
    "bio": "Updated bio text"
  }

• Response (200 OK): UserResponse

2. Question Management

Base Path: /questions

2.1 Add Question

Post a new question to the platform.

• Endpoint: POST /questions

• Request Body:

  {
    "title": "How does Spring Boot handle dependency injection?",
    "body": "I am trying to understand the internal working of IoC container...",
    "userId": "123e4567-e89b-12d3-a456-426614174000",
    "topics": ["Java", "Spring Boot", "Programming"]
  }

• Response (201 Created):

  {
    "id": "a1b2c3d4-e5f6-7890-1234-567890abcdef",
    "title": "How does Spring Boot handle dependency injection?",
    "body": "I am trying to understand the internal working of IoC container...",
    "username": "johndoe",
    "topics": ["Java", "Spring Boot"],
    "answers": [],
    "likes": []
  }

2.2 Search Questions

Search for questions by text content or specific topic tags.

• Endpoint: GET /questions/search

• Query Parameters:

text (optional): Keyword search for title/body

tag (optional): Filter by topic

• Response (200 OK): List<QuestionResponse>

3. Answer Management

Base Path: /answers

3.1 Get All Answers

Retrieve all answers available in the database.

• Endpoint: GET /answers

• Response (200 OK): List<AnswerResponse>

3.2 Add Answer

Submit an answer to a specific question.

• Endpoint: POST /answers/{questionId}

• Path Parameters:

questionId: UUID of the question being answered

• Request Body:

  {
    "userId": "123e4567-e89b-12d3-a456-426614174000",
    "text": "Spring Boot uses the ApplicationContext to manage beans..."
  }

• Response (201 Created):

  {
    "answerId": "987fcdeb-5432-10fe-ba98-765432101234",
    "text": "Spring Boot uses the ApplicationContext to manage beans...",
    "user": "johndoe",
    "question": "How does Spring Boot handle dependency injection?",
    "comments": [],
    "likes": []
  }

3.3 Edit Answer

Modify the text of an existing answer.

• Endpoint: PUT /answers/{answerId}

• Request Body: (String) "Updated answer text content..."

• Response (200 OK): AnswerResponse

4. Comment Management

• Base Path: /comments

4.1 Add Comment on Answer

Add a comment directly to an answer.

• Endpoint: POST /comments/{answerId}/answer

• Request Body:

  {
    "userId": "123e4567-e89b-12d3-a456-426614174000",
    "answerId": "987fcdeb-5432-10fe-ba98-765432101234",
    "text": "Great explanation!",
    "parentCommentId": null
  }

• Response (201 Created): CommentResponse

4.2 Reply to Comment

Add a nested reply to an existing comment.

• Endpoint: POST /comments/{commentId}/comment

• Request Body:

  {
    "userId": "123e4567-e89b-12d3-a456-426614174000",
    "answerId": "987fcdeb-5432-10fe-ba98-765432101234",
    "text": "I agree with this point.",
    "parentCommentId": "existing-comment-uuid"
  }

• Response (201 Created): CommentResponse

4.3 Get Comment

Retrieve a single comment by ID.

• Endpoint: GET /comments/{commentId}

• Response (200 OK):

  {
    "commentId": "uuid-string",
    "user": "username",
    "answer": "answer-text-preview",
    "text": "Great explanation!",
    "parentComment": "parent-username-or-null",
    "childComments": []
  }

5. Topic Management

Base Path: /topics

5.1 Create Topic

Create a new topic tag for categorizing questions.

• Endpoint: POST /topics

• Request Body: (String) "Microservices"

• Response (201 Created): (String) "Microservices"

5.2 Get All Topics

Retrieve a list of all available topics.

• Endpoint: GET /topics

• Response (200 OK): ["Java", "Microservices", "Spring Boot"]

6. Social Interactions

6.1 Follow User

Create a follower relationship between two users.

• Endpoint: POST /follow/{userId}/follows/{targetUserId}

• Path Parameters:

userId: UUID of the follower

targetUserId: UUID of the user being followed

Response: 201 Created (Empty Body)

6.2 Like Entity

Add a like to a Question, Answer, or Comment.

• Endpoint: POST /likes/{type}/{id}

• Path Parameters:

type: The type of entity (e.g., question, answer, comment)

id: The UUID of the specific entity

• Request Body:

  {
    "userId": "123e4567-e89b-12d3-a456-426614174000"
  }

• Response: 201 Created (Empty Body)

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Project Structure

com.example.QuoraAPI
├── controllers   # REST Controllers (Endpoints)
├── dto           # Data Transfer Objects (Request/Response models)
├── services      # Business Logic
├── repositories  # Database Access (JPA Interfaces)
└── models        # JPA Entities (Database Tables)