GraphQL实战-第三篇-spring Boot 实现

在上一篇的java实现中，分享了使用GraphQL的基本流程，接下来分享一下在Spring Boot中对GraphQL的应用

首先创建一个Spring Boot的项目

POM依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.3.4.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.clc</groupId>
	<artifactId>boot</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>boot</name>
	<description>Demo project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>
		<dependency>
			<groupId>com.graphql-java</groupId>
			<artifactId>graphql-java</artifactId>
			<version>15.0</version>
		</dependency>
		<!--lombok-->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<version>1.18.4</version>
		</dependency>

	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

创建schema

接下来就是创建一个schema的文件，来写graphql的定义，这里还用之前的例子。resources下创建一个user.graphqls。

#对应的User定义如下
schema {
    #定义查询
    query: UserQuery
}

#定义查询类型
type UserQuery {
    #指定对象以及参数类型
    queryUser : User
    queryUserById(id:ID) : User
}

#定义对象
type User {
    #!表示非空
    id:ID!
    name:String
    age:Int
    card:Card
}

type Card {
    cardNumber:String
    userId:ID
}

Java实现

数据操作对应的java对象

package com.clc.boot.bean;

import lombok.Data;

/**
 * ClassName: User<br/>
 * Description: <br/>
 * date: 2019/6/28 10:38 AM<br/>
 *
 * @author chengluchao
 * @since JDK 1.8
 */
@Data
public class User {
    private int age;
    private long id;
    private String name;
    private Card card;

    public User(int age, long id, String name, Card card) {
        this.age = age;
        this.id = id;
        this.name = name;
        this.card = card;
    }

    public User(int age, long id, String name) {
        this.age = age;
        this.id = id;
        this.name = name;
    }
}

package com.clc.boot.bean;

import lombok.Data;

/**
 * ClassName: Card<br/>
 * Description: <br/>
 * date: 2019/6/28 3:25 PM<br/>
 *
 * @author chengluchao
 * @since JDK 1.8
 */
@Data
public class Card {
    private String cardNumber;
    private Long userId;

    public Card(String cardNumber, Long userId) {
        this.cardNumber = cardNumber;
        this.userId = userId;
    }
}

解析GraphQL的核心类

package com.clc.boot.graphql;

import com.clc.boot.bean.User;
import com.clc.boot.bean.Card;
import graphql.GraphQL;
import graphql.schema.GraphQLSchema;
import graphql.schema.idl.RuntimeWiring;
import graphql.schema.idl.SchemaGenerator;
import graphql.schema.idl.SchemaParser;
import graphql.schema.idl.TypeDefinitionRegistry;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.util.ResourceUtils;

import javax.annotation.PostConstruct;
import java.io.File;
import java.io.IOException;

/**
 * 实现功能：将GraphQL对象载入待Spring容器，并且完成GraphQL对象初始化的功能
 *
 * @author chengluchao
 */
@Component
public class GraphQLProvider {


    private GraphQL graphQL;

    @Bean
    public GraphQL graphQL() {
        return graphQL;
    }

    /**
     * 加载schema
     *
     * @throws IOException
     */
    @PostConstruct
    public void init() throws IOException {
        File file = ResourceUtils.getFile("classpath:user.graphqls");
        GraphQLSchema graphQLSchema = buildGraphQLSchema(file);
        this.graphQL = GraphQL.newGraphQL(graphQLSchema).build();
    }

    private GraphQLSchema buildGraphQLSchema(File file) {
        TypeDefinitionRegistry typeRegistry = new SchemaParser().parse(file);
        GraphQLSchema graphQLSchema = new SchemaGenerator().makeExecutableSchema(typeRegistry, buildWiring());
        return graphQLSchema;
    }

    private GraphQLSchema buildSchema(String sdl) {
        TypeDefinitionRegistry typeRegistry = new SchemaParser().parse(sdl);
        RuntimeWiring runtimeWiring = buildWiring();
        SchemaGenerator schemaGenerator = new SchemaGenerator();
        return schemaGenerator.makeExecutableSchema(typeRegistry, runtimeWiring);
    }

    /**
     * 业务实现，demo版
     * 如果是开发实战，这一点的设计是重点，需要考虑如何根据graphql中定义的方法来执行java代码
     *
     * @return
     */
    private RuntimeWiring buildWiring() {
        RuntimeWiring wiring = RuntimeWiring.newRuntimeWiring()
                .type("UserQuery", builder ->
                        builder.dataFetcher("queryUserById", environment -> {
                            Long id = Long.parseLong(environment.getArgument("id"));
                            Card card = new Card("123456", id);
                            return new User(18, id, "user0" + id, card);
                        })
                )
                .build();
        return wiring;
    }
}

接下来是GraphQL的入口：

package com.clc.boot.controller;

import graphql.ExecutionResult;
import graphql.GraphQL;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;


/**
 * ClassName: GraphQLController<br/>
 * Description: <br/>
 * date: 2019/6/28 5:38 PM<br/>
 *
 * @author chengluchao
 * @since JDK 1.8
 */
@RequestMapping("graphql")
@Controller
public class GraphQLController {
    @Autowired
    private GraphQL graphQL;

    @RequestMapping("query")
    @ResponseBody
    public Object query(@RequestParam("query") String query) {
        ExecutionResult result = this.graphQL.execute(query);
        return result.toSpecification();
    }
}

测试：

127.0.0.1:8080/graphql/query?query={ user: queryUserById(id:15){id,name,age,card{cardNumber,userId}}}

{
    "data": {
        "user": {
            "id": "15",
            "name": "user015",
            "age": 18,
            "card": {
                "cardNumber": "123456",
                "userId": "15"
            }
        }
    }
}

源码地址：https://gitee.com/chengluchao/graphql-clc/tree/master/graphql-springboot
这里实现了graphql在spring-boot中的应用，由于解析graphql到业务执行还不够自动化，所以此例子还是一个demo级别

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