Spring Boot集成Graphql快速入门Demo

1.Graphql介绍

优势

1. GraphQL 速度快，并且比较稳定，GraphQL 的操作是在数据层面的，所以比较快。
2. GraphQL 可以获取更多的资源，当查询一个数据的时候，不止是这个数据，甚至可以很快地查询到数据引用的另一个数据。GraphQL 可以在单个请求中去获取尽量多的数据，并且在弱网状态下，GraphQL 依旧表现出色。
3. GraphQL 是单端点查询，并在此端点中去完成所有的查询。
4. GraphQL 的可持续性非常出色，无论是新字段、还是旧字段，它都能很好地去处理，可维护性也极佳。
5. GraphQL 具有向下兼容的特性，就算是很久很久以前的功能，GraphQL 还是能很好地去兼容它，保证旧版本的正常运行，同时又不影响新功能的加入以及整体的稳定性。这样做的好处就是，不需要去担忧版本号问题了。
6. GraphQL 具有强类型，在 GraphQL 的查询中，一个级别对应一个强类型，这个类型充当一个字段的描述。这样的好处就是，在查询之前，可以校验出错误并提示，方便定位问题，提高性能。
7. 自省：可以查询 GraphQL 服务器支持的类型。这为工具和客户端软件创建了一个强大的平台，可以在这些信息的基础上构建静态类型语言的代码生成、我们的应用程序框架、Relay 或 GraphiQL 等 IDE。
8. GraphQL 支持使用者去决定服务器支持的类型。这样的好处就是，给很多使用 GraphQL 的 工具或者端建立了一个比较成熟且强大的应用平台，通过这个平台，一些框架、工具得到不断地优化提升。

劣势

1. GraphQL 无法完成深度查询，所以无法对于未知深度的数据进行一次性查询。
2. GraphQL 具有非常死板的响应结构，你必须遵从这个结构去查询数据，或者自己添加一个转换器来转换。
3. GraphQL 无法进行网络级别的缓存，你必须使用另外别的办法进行持久查询。
4. GraphQL 默认没有上传文件的功能，GraphQL 也不接收文件类型的参数，但是你可以使用 REST 的方式进行上传文件，达到上传文件的目的。
5. GraphQL 的执行是不可预测的，因为 GraphQL 太过于灵活了。
6. 同样的一个简单的 API，GraphQL 会表现得很复杂，所以建议简单 API 使用 RSET。

2.mysql环境搭建

version: '3'
services:
  mysql:
    image: registry.cn-hangzhou.aliyuncs.com/zhengqing/mysql:5.7
    container_name: mysql_3306
    restart: unless-stopped                                   
    volumes:
      - "./mysql/my.cnf:/etc/mysql/my.cnf"
      - "./mysql/init-file.sql:/etc/mysql/init-file.sql"
      - "./mysql/data:/var/lib/mysql"
#      - "./mysql/conf.d:/etc/mysql/conf.d"
      - "./mysql/log/mysql/error.log:/var/log/mysql/error.log"
      - "./mysql/docker-entrypoint-initdb.d:/docker-entrypoint-initdb.d" # init sql script directory -- tips: it can be excute  when `/var/lib/mysql` is empty
    environment:                        # set environment,equals docker run -e
      TZ: Asia/Shanghai
      LANG: en_US.UTF-8
      MYSQL_ROOT_PASSWORD: root         # set root password
      MYSQL_DATABASE: demo              # init database name
    ports:                              # port mappping
      - "3306:3306"

docker-compose -f docker-compose.yml -p mysql5.7 up -d

CREATE DATABASE IF NOT EXISTS `BOOK_API_DATA`;
USE `BOOK_API_DATA`;

CREATE TABLE IF NOT EXISTS `Book` (
    `id` int(20) NOT NULL AUTO_INCREMENT,
    `name` varchar(255) DEFAULT NULL,
    `pageCount` varchar(255) DEFAULT NULL,
    PRIMARY KEY (`id`),
    UNIQUE KEY `Index_name` (`name`)
    ) ENGINE=InnoDB AUTO_INCREMENT=235 DEFAULT CHARSET=utf8;

CREATE TABLE `Author` (
     `id` INT(20) NOT NULL AUTO_INCREMENT,
     `firstName` VARCHAR(255) NULL DEFAULT NULL COLLATE 'utf8_general_ci',
     `lastName` VARCHAR(255) NULL DEFAULT NULL COLLATE 'utf8_general_ci',
     `bookId` INT(20) NULL DEFAULT NULL,
     PRIMARY KEY (`id`) USING BTREE,
     UNIQUE INDEX `Index_name` (`firstName`) USING BTREE,
     INDEX `FK_Author_Book` (`bookId`) USING BTREE,
     CONSTRAINT `FK_Author_Book` FOREIGN KEY (`bookId`) REFERENCES `BOOK_API_DATA`.`Book` (`id`) ON UPDATE CASCADE ON DELETE CASCADE
)
    COLLATE='utf8_general_ci'
ENGINE=InnoDB
AUTO_INCREMENT=6
;



INSERT INTO `Book` (`id`, `name`, `pageCount`) VALUES (1, 'the golden ticket', '255');
INSERT INTO `Book` (`id`, `name`, `pageCount`) VALUES (2, 'coding game', '300');

INSERT INTO `Author` (`id`, `firstName`, `LastName`, `bookId`) VALUES (4, 'Brendon', 'Bouchard', 1);
INSERT INTO `Author` (`id`, `firstName`, `LastName`, `bookId`) VALUES (5, 'John', 'Doe', 2);

3.代码工程

 实验目标

实现过程

1. 定义Schema，Schema使用GraphQL Schema Definition Language (SDL)来定义

2. 实现Resolver，Resolver函数负责从数据源中获取请求的数据

3. 配置和启动GraphQL服务器 ，要启动GraphQL服务器，你需要安装相应的依赖和配置服务器

pomxml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springboot-demo</artifactId>
        <groupId>com.et</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>GraphQL</artifactId>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <kotlin.version>1.5.0</kotlin.version>
    </properties>
    <dependencies>

        <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>
            <version>12.0.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <dependency>
            <groupId>com.graphql-java-kickstart</groupId>
            <artifactId>graphql-java-tools</artifactId>
            <version>12.0.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>com.google.guava</groupId>
            <artifactId>guava</artifactId>
            <version>26.0-jre</version>
        </dependency>

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>
</project>

GraphQLQueryResolver

package com.et.graphql.queryresolvers;

import com.et.graphql.model.Author;
import com.et.graphql.model.Book;
import com.et.graphql.repository.AuthorRepository;
import com.et.graphql.repository.BookRepository;
import graphql.kickstart.tools.GraphQLQueryResolver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;


@Component
public class BookQuery implements GraphQLQueryResolver{

    @Autowired
    BookRepository bookRepository;
    @Autowired
    AuthorRepository authorRepository;

    public Iterable<Book> allBook(){
        return bookRepository.findAll();
    }

    public Book getBookByName(String name){
        return bookRepository.findBookByName(name);
    }

    public Iterable<Author> allAuthor(){
        return authorRepository.findAll();
    }

}

package com.et.graphql.queryresolvers;

import com.et.graphql.model.Book;
import com.et.graphql.repository.BookRepository;
import graphql.kickstart.tools.GraphQLMutationResolver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.util.Optional;

@Component
public class BookMutation implements GraphQLMutationResolver {

    @Autowired
    BookRepository bookRepository;

    public Book newBook(String name, String pageCount){
        Book book =  new Book();
        book.setName(name);
        book.setPageCount(pageCount);
        return bookRepository.save(book);
    }

    public Book deleteBook(Integer id){
        Book deleteBook = new Book();
        Optional<Book> findBook =  bookRepository.findById(id);
        if(findBook.isPresent()){
            bookRepository.delete(findBook.get());
            deleteBook = findBook.get();
        }
        return deleteBook;
    }
}

package com.et.graphql.queryresolvers;


import com.et.graphql.model.Author;
import com.et.graphql.model.Book;
import com.et.graphql.repository.AuthorRepository;
import graphql.kickstart.tools.GraphQLResolver;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class BookAuthorResolver implements GraphQLResolver<Book> {

    @Autowired
    AuthorRepository authorRepository;

    public Author getAuthor(Book book){

        return authorRepository.findAuthorByBookId(book.getId());
    }
}

type Book {
    id: Int
    name: String
    pageCount: String
    author: Author
}

type Query {
    allBook: [Book]
    allAuthor:[Author]
    getBookByName(name: String): Book
}

type Mutation {
    newBook(name: String!, pageCount: String): Book
    deleteBook(id:Int!):Book
}



type Author {
    id: Int
    firstName: String
    lastName: String
    bookId: Int
}

model

package com.et.graphql.model;


import javax.persistence.*;

@Entity
@Table(name = "Author", schema = "BOOK_API_DATA")
public class Author {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    Integer id;
    @Column(name = "firstname")
    String firstName;
    @Column(name = "lastname")
    String lastName;
    @Column(name = "bookid")
    Integer bookId;

    public Author(Integer id, String firstName, String lastName, Integer bookId) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.bookId = bookId;
    }

    public Author() {

    }

    public Integer getId() {
        return id;
    }

    public String getFirstName() {
        return firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Integer getBookId() {
        return bookId;
    }

    public void setBookId(Integer bookId) {
        this.bookId = bookId;
    }
}

package com.et.graphql.model;

import javax.persistence.*;

@Entity
@Table(name = "Book", schema = "BOOK_API_DATA")
public class Book {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;
    private String name;
    @Column(name = "pagecount")
    private String pageCount;

    public Book(Integer id, String name, String pageCount) {
        this.id = id;
        this.name = name;
        this.pageCount = pageCount;
    }

    public Book() {

    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPageCount() {
        return pageCount;
    }

    public void setPageCount(String pageCount) {
        this.pageCount = pageCount;
    }
}

repository

package com.et.graphql.repository;

import com.et.graphql.model.Author;
import org.springframework.data.repository.CrudRepository;

public interface AuthorRepository extends CrudRepository<Author, Integer> {

    Author findAuthorByBookId(Integer bookId);
}

package com.et.graphql.repository;


import com.et.graphql.model.Book;
import org.springframework.data.repository.CrudRepository;

public interface BookRepository extends CrudRepository<Book, Integer> {

    Book findBookByName(String name);
}

DemoApplication.java

package com.et.graphql;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;

@SpringBootApplication
@ComponentScan(basePackages = "com.et.graphql.queryresolvers")
public class BookAPIApplication {

    public static void main(String[] args) {
        SpringApplication.run(BookAPIApplication.class, args);
    }

}

application.yaml

spring.jpa.hibernate.ddl-auto=none
spring.jpa.database=mysql
spring.jpa.open-in-view=true
spring.jpa.show-sql=true
server.port=8088
#logging.level.org.hibernate=DEBUG
logging.level.org.hibernate.SQL=DEBUG
spring.jpa.hibernate.naming.physical-strategy=org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
spring.jpa.hibernate.use-new-id-generator-mappings= false

# book api db"
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/demo?useUnicode=true&characterEncoding=utf-8&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

• https://github.com/Harries/springboot-demo

4.测试

 query {
 allBook{
 id
 name
 pageCount
 }
 }

5.引用

• https://www.cnblogs.com/zcqiand/p/18011513
• http://www.liuhaihua.cn/archives/710416.html
• https://graphql.org/