Spring Boot GraphQL Http GraphQL Client

Spring Boot provides a WebClient Interface for HTTP API calls, and Spring Boot GraphQL provides a HttpGraphQlClient Interface that is a wrapper around the WebClient Interface.

package org.wesome.graphql.controllers;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.graphql.client.GraphQlClient;
import org.springframework.graphql.client.HttpGraphQlClient;
import org.springframework.graphql.data.method.annotation.QueryMapping;
import org.springframework.stereotype.Controller;
import org.springframework.web.reactive.function.client.WebClient;
import org.wesome.graphql.entity.Apple;
import org.wesome.graphql.service.AppleService;
import reactor.core.publisher.Mono;

import java.util.List;

@Controller
public record AppleGraphQLController(@Autowired AppleService appleService, @Value("${graphql.apple.query}") String query) {
    @QueryMapping("apples")
    public List<Apple> apples() {
        return appleService.findAllApple();
    }

    @QueryMapping("applesWebService")
    public Mono<List<Apple>> applesWebService() {
        WebClient client = WebClient.builder().baseUrl("http://localhost:8080/graphql").build();
        GraphQlClient graphQlClient = HttpGraphQlClient.builder(client).build();
        Mono<List<Apple>> countries = graphQlClient.document(query).retrieve("apples").toEntityList(Apple.class);
        return countries;
    }
}

package org.wesome.graphql.data;

public enum AppleName {
    MACINTOSH("Macintosh"),
    FUJI("Fuji"),
    GALA("Gala"),
    JONAGOLD("Jonagold");
    private String appleName;

    AppleName(String appleName) {
        this.appleName = appleName;
    }
}

package org.wesome.graphql.entity;

public record Apple(int appleId, String appleName, Float price, Boolean available, String time) {
}

package org.wesome.graphql.service;

import org.wesome.graphql.entity.Apple;

import java.util.List;

public interface AppleService {
    List<Apple> findAllApple();
}

package org.wesome.graphql.service;

import org.springframework.stereotype.Service;
import org.wesome.graphql.entity.Apple;

import java.util.List;

import static org.wesome.graphql.GraphqlProjectApplication.apples;

@Service
public record AppleServiceImpl() implements AppleService {
    @Override
    public List<Apple> findAllApple() {
        return apples;
    }
}

package org.wesome.graphql;

import com.github.javafaker.Faker;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.wesome.graphql.data.AppleName;
import org.wesome.graphql.entity.Apple;

import java.time.LocalTime;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@SpringBootApplication
public class GraphqlProjectApplication implements CommandLineRunner {
    public static List<Apple> apples;

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

    @Override
    public void run(String... args) {
        Faker faker = new Faker();
        apples = IntStream.rangeClosed(0, AppleName.values().length - 1).mapToObj(app -> new Apple(app, AppleName.values()[app].name(), Float.valueOf(app), faker.random().nextBoolean(), LocalTime.now().toString())).collect(Collectors.toList());
    }
}

\src\main\resources\graphql\schema.graphqls 

# Apple Object
type Apple{
    # primary key of apple
    appleId:ID!
    # apple Name
    appleName:String
    # apple price
    price:Float
    # apple Availability
    available:Boolean
    # current time
    time:String
}

# Apple Query
type Query{
    # query to get all apples
    apples:[Apple]
    # query to get all apples via HTTP request
    applesWebService:[Apple]
}

\src\main\resources\application.properties 

spring.graphql.graphiql.enabled=true
spring.graphql.websocket.path=/graphql
graphql.apple.query=query Apples { apples { appleId appleName price available time }}

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
         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>3.1.5</version>
        <relativePath/>
    </parent>
    <groupId>org.wesome</groupId>
    <artifactId>spring-boot-graphql</artifactId>
    <version>0.0.1-snapshot</version>
    <name>spring-boot-graphql</name>
    <description>implementing graphql in spring boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.javafaker</groupId>
            <artifactId>javafaker</artifactId>
            <version>1.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-graphql</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.graphql</groupId>
            <artifactId>spring-graphql-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

curl --location --request POST 'http://localhost:8080/graphql' \
--header 'Content-Type: application/json' \
--data '{"query":"query ApplesWebService {\r\n    applesWebService {\r\n        appleId\r\n        appleName\r\n        price\r\n        available\r\n        time\r\n    }\r\n}\r\n","variables":{}}'

GraphiQL

GraphQL provides an inbuild UserInterface GraphiQL, which can be accessed via http://localhost:8080/graphiql or access GraphQL via Postman, in the query section add the below query

query ApplesWebService {
    applesWebService {
        appleId
        appleName
        price
        available
        time
    }
}