Spring Boot GraphQL Custom Instrumentation

Spring Boot GraphQL allows custom instrumentation by implementing an Instrumentation Interface. All Custom Instrumentation must have a @Component annotation, Spring boot will register all Components at startup time.  Below is an example of Spring Boot GraphQL Custom Instrumentation for query response and computation time taken.

package org.wesome.graphql.controllers;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.graphql.data.method.annotation.QueryMapping;
import org.springframework.stereotype.Controller;
import org.wesome.graphql.entity.Apple;
import org.wesome.graphql.service.AppleService;

import java.util.List;

@Controller
public class AppleGraphQLController {
    @Autowired
    private AppleService appleService;

    @QueryMapping("findAllApple")
    List<Apple> findAllApple() {
        return appleService.findAllApple();
    }
}

package org.wesome.graphql.configuration;

import com.google.gson.Gson;
import graphql.ExecutionResult;
import graphql.execution.instrumentation.InstrumentationContext;
import graphql.execution.instrumentation.InstrumentationState;
import graphql.execution.instrumentation.SimplePerformantInstrumentation;
import graphql.execution.instrumentation.parameters.InstrumentationExecutionParameters;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import java.text.MessageFormat;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.AtomicLong;

@Component
public class QueryInstrumentation extends SimplePerformantInstrumentation {
    @Autowired
    private Gson gson;

    @Override
    public InstrumentationContext<ExecutionResult> beginExecution(InstrumentationExecutionParameters parameters, InstrumentationState state) {
        return new InstrumentationContext<>() {
            AtomicLong startTime = new AtomicLong();

            @Override
            public void onDispatched(CompletableFuture<ExecutionResult> result) {
                startTime.set(System.currentTimeMillis());
            }

            @Override
            public void onCompleted(ExecutionResult result, Throwable t) {
                System.out.println(MessageFormat.format("Query execution time {1} millisecond, Response is {0}  ", gson.toJson(result), System.currentTimeMillis() - startTime.get()));
            }
        };
    }
}

package org.wesome.graphql.entity;

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

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.ArrayList;
import java.util.List;

@Service
public class AppleServiceImpl implements AppleService {
    private static final List<Apple> apples = new ArrayList<>(List.of(new Apple(1, "Macintosh", 1.1F, true), new Apple(2, "Fuji", 2.2F, true), new Apple(3, "Gala", 3.3F, true), new Apple(4, "Jonagold", 4.4F, true)));
    @Override
    public List<Apple> findAllApple() {
        return apples;
    }
}

package org.wesome.graphql;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.wesome.graphql.entity.Apple;

import java.util.List;

@SpringBootApplication
public class GraphqlProjectApplication {

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

    @Bean
    public Gson gson() {
        return new GsonBuilder().serializeNulls().setPrettyPrinting().create();
    }
}

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

# Apple Query
type Query{
    # query to get all apples
    findAllApple:[Apple]
}

\src\main\resources\application.properties

spring.graphql.graphiql.enabled=true

pom.xml

<?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>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.10.1</version>
        </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</groupId>
            <artifactId>spring-webflux</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>

Rest API

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