Book details tutorial example

This repository contains the source code for the tutorial "Getting started with GraphQL Java and Spring Boot" which is available here: https://www.graphql-java.com/tutorials/getting-started-with-spring-boot/

加料版

1增加了maven支持 2访问路径http://localhost:8080/graphql，参数：

{
    bookById(id:"book-1"){
        id
        name
        pageCount
        author{
            id
            lastName
            firstName
        }
    }
}

3客户端批量请求处理，spring.graphql.batch.enabled不支持，应该是版本低，没有继续试了；原则是支持批处理的；