Library Application API

Overview

This is a RESTful API for managing books in a library. The API provides functionalities to:

• Retrieve book information by ISBN.
• Find books by author name.
• Add new books.
• Remove books by ISBN.
• Increment or decrement the available copies of a book.

The API follows RESTful principles and returns appropriate HTTP status codes for success and failure scenarios.

Endpoints

1. Find a Book by ISBN

Endpoint: GET /api/books/{isbn}
Description: Retrieves a book's details using its ISBN number.

• Path Parameter:

  • isbn (String) - The ISBN number of the book.

• Response:

  • 200 OK - Returns the BookDTO object with details of the book.
  • 404 Not Found - If no book with the given ISBN is found.

Example Request:

GET /books/978-3-16-148410-0

Example Response:

{
  "isbn": "978-3-16-148410-0",
  "title": "The Nizams of Hyderabad",
  "author": "F. Scott Fitzgerald",
  "publicationYear": 1925,
  "availableCopies": 12
}

---

2. Find Books by Author Name

Endpoint: GET /api/books
Description: Retrieves a list of books by the specified author.

• Query Parameter:

  • authorName (String) - The name of the author.

• Response:

  • 200 OK - Returns a list of BookDTO objects by the author.
  • 404 Not Found - If no books by the given author are found.

Example Request:

GET /api/books?authorName=F.%20Scott%20Fitzgerald

Example Response:

[
  {
    "isbn": "978-3-16-148410-0",
    "title": "The Nizams of Hyderabad",
    "author": "F. Scott Fitzgerald",
    "publicationYear": 1925,
    "availableCopies": 12
  }
]

---

3. Remove a Book by ISBN

Endpoint: DELETE /api/books/{isbn}
Description: Deletes a book from the library's collection by ISBN.

• Path Parameter:

  • isbn (String) - The ISBN number of the book.

• Response:

  • 204 No Content - If the book is successfully deleted.
  • 404 Not Found - If no book with the given ISBN is found.

Example Request:

DELETE /api/books/978-3-16-148410-0

---

4. Create a New Book

Endpoint: POST /api/books
Description: Adds a new book to the library.

• Request Body:

  • BookResource - A JSON object containing details of the new book.

• Response:

  • 201 Created - Returns the created BookDTO object.
  • 400 Bad Request - If the request body is invalid.

Example Request:

POST /api/books
{
  "title": "The Nizams of Hyderabad",
  "author": "Adam Harper",
  "publicationYear": 1960,
  "availableCopies": 5
}

Example Response:

{
  "isbn": "978-0-7432-7356-5",
  "title": "The Nizams of Hyderabad",
  "author": "Adam Harper",
  "publicationYear": 1960,
  "availableCopies": 5
}

---

5. Increment Available Copies of a Book

Endpoint: PATCH /api/books/{isbn}/available-copies/increment
Description: Increases the number of available copies for a book by 1.

• Path Parameter:

  • isbn (String) - The ISBN number of the book.

• Response:

  • 200 OK - Returns the updated BookDTO object with incremented available copies.
  • 404 Not Found - If no book with the given ISBN is found.

Example Request:

PATCH /api/books/978-3-16-148410-0/available-copies/increment

Example Response:

{
  "isbn": "978-3-16-148410-0",
  "title": "The Nizams of Hyderabad",
  "author": "F. Scott Fitzgerald",
  "publicationYear": 1925,
  "availableCopies": 13
}

---

6. Decrement Available Copies of a Book

Endpoint: PATCH /api/books/{isbn}/available-copies/decrement
Description: Decreases the number of available copies for a book by 1.

• Path Parameter:

  • isbn (String) - The ISBN number of the book.

• Response:

  • 200 OK - Returns the updated BookDTO object with decremented available copies.
  • 400 Bad Request - If decrementing would result in negative available copies.
  • 404 Not Found - If no book with the given ISBN is found.

Example Request:

PATCH /api/books/978-3-16-148410-0/available-copies/decrement

Example Response:

{
  "isbn": "978-3-16-148410-0",
  "title": "The Nizams of Hyderabad",
  "author": "F. Scott Fitzgerald",
  "publicationYear": 1925,
  "availableCopies": 11
}

---

Data Models

BookDTO

Represents the data returned for a book.

{
  "isbn": "string",
  "title": "string",
  "author": "string",
  "publicationYear": "int",
  "availableCopies": "int"
}

BookResource

Represents the data required to create a new book.

{
  "isbn": "string",
  "title": "string",
  "author": "string",
  "publicationYear": "int",
  "availableCopies": "int"
}

---

Error Handling

• 404 Not Found: If a book with the specified isbn or authorName is not found.
• 400 Bad Request: If invalid input is provided, such as an invalid request body during book creation.
• 204 No Content: If a delete request is successful.

---

Getting Started

1. Clone the repository.
2. Ensure you have a valid database connection set up in your application.properties or application.yml.
3. Run the application using a Java IDE or build tool like Maven or Gradle.
4. Please find the file Library REST APIs.postman_collection to help with running APIs in postman.