Spring Boot with GraphQL

Creating a GraphQL API with Spring Boot involves integrating the GraphQL Java library into your Spring Boot application.

To use GraphQL with Spring Boot, you can leverage the spring-graphql module, which provides integration with the GraphQL Java implementation. Here are the steps to set up a Spring Boot project with GraphQL

Create a Spring Boot Project

You can use Spring Initializer (https://start.spring.io/) or your favorite IDE to create a new Spring Boot project. Make sure to include the "Spring Web" and "GraphQL" dependencies.

Add GraphQL Dependencies

Open your pom.xml file and make sure it includes the necessary dependencies. Here is an example

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>com.graphql-java-kickstart</groupId>
    <artifactId>graphql-spring-boot-starter</artifactId>
</dependency>
<dependency>
    <groupId>com.graphql-java-kickstart</groupId>
    <artifactId>graphql-java-tools</artifactId>
</dependency>

Create GraphQL Schema

Create a GraphQL schema file (usually with a .graphqls extension) where you define your types and queries. Place it in the src/main/resources directory. Here's a simple example:

type Book {

    id: ID!
    author: String
    title: String
    description: String
    pages: Int
    price: Float
    publisher: String

}

type Mutation {

    createBook(bookInput: CreateBookInput) : Book
    updateBook(bookInput: UpdateBookInput) : Book
    deleteBook(bookId : Int) : Boolean


}


type Query {
    allBooks : [Book]
    getBookById(bookId:Int ) : Book
}


input CreateBookInput {
    author: String
    title: String
    description: String
    pages: Int
    price: Float
    publisher: String

}
input UpdateBookInput {
    id: ID!
    author: String
    title: String
    description: String
    pages: Int
    price: Float
    publisher: String

}

Note: This is a basic setup, and you can explore code for your better understading, how we are using GraphQL in Spring Boot application.

GraphQL API Endpoints

Get Book by ID

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

query {
  getBookById(bookId: 2) {
    id
    author
    description
    title
    publisher
    price
    pages
  }
}

Get All Books [ Example 1 ]

Example one with all details(id, title, author, description, publisher, price and pages).

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

query {
  allBooks {
    id
    title
    author
    description
    publisher
    price
    pages
  }
}

Get All Books [ Example 2 ]

Another example with few details(title, author and description).

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

query {
  allBooks {
    title
    author
    description
  }
}

Create Book

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

mutation {
  createBook(
    bookInput: {
      title: "Black Hat GraphQL"
      author: "Nick Aleks"
      description: "Black Hat GraphQL is for anyone interested in learning how to break and protect GraphQL APIs with the aid of offensive security testing."
      publisher: "Opheliar Chan"
      price: 1200.0
      pages: 263
    }
  ) {
    id
    title
    author
    description
    publisher
    price
    pages
  }
}

Update Book

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

mutation {
  updateBook(
    bookInput: {
      id : 2
      title: "GraphQL in Action"
      author: "Samer Buna"
      description: "GraphQL in Action gives you the tools to get comfortable with the GraphQL language, build and optimize a data API service, and use it in a front-end client application."
      publisher: "Manning Publications"
      price: 2200.0
      pages: 800
    }
  ) {
    id
    title
    author
    description
    publisher
    price
    pages
  }
}

Delete Book

Method: POST

Endpoint: http://localhost:8080/api/graphql

Request Payload: Select Body -> GraphQL and put below payload sample in Query

mutation {
  deleteBook(bookId: 3)
}

These are the GraphQL API endpoints and operations available for managing books.