Spring Boot GraphQL Validation NotEmpty

The NotEmpty Validation Directive is applied to the String and checks if it's not empty.

package org.wesome.graphql.config;

import graphql.validation.rules.ValidationRules;
import graphql.validation.schemawiring.ValidationSchemaWiring;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.graphql.execution.RuntimeWiringConfigurer;

@Configuration
public class GraphQlConfig {
    @Bean
    RuntimeWiringConfigurer runtimeWiringConfigurer() {
        ValidationRules possibleRules = ValidationRules.newValidationRules().build();
        ValidationSchemaWiring validationDirectiveWiring = new ValidationSchemaWiring(possibleRules);
        return wiringBuilder -> wiringBuilder.directiveWiring(validationDirectiveWiring);
    }
}

package org.wesome.graphql.controllers;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.graphql.data.method.annotation.Argument;
import org.springframework.graphql.data.method.annotation.MutationMapping;
import org.springframework.graphql.data.method.annotation.QueryMapping;
import org.springframework.stereotype.Controller;
import org.wesome.graphql.entity.Apple;
import org.wesome.graphql.entity.AppleVO;
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();
    }

    @MutationMapping("addApple")
    Apple addApple(@Argument AppleVO appleVO) {
        return appleService.addApple(appleVO);
    }
}

package org.wesome.graphql.entity;

public record Apple(int appleId, String appleName, int quantity) {
}

package org.wesome.graphql.entity;

public record AppleVO(int appleId, String appleName, int quantity) {
}

package org.wesome.graphql.service;

import org.wesome.graphql.entity.Apple;
import org.wesome.graphql.entity.AppleVO;

import java.util.List;

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

    Apple addApple(AppleVO appleVO);
}

package org.wesome.graphql.service;

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

import java.util.ArrayList;
import java.util.List;

@Service
public class AppleServiceImpl implements AppleService {
    private static List<Apple> apples = new ArrayList<>();

    @Override
    public List<Apple> findAllApple() {
        return apples;
    }

    @Override
    public Apple addApple(AppleVO appleVO) {
        Apple apple = new Apple(apples.size() + 1, appleVO.appleName(), appleVO.quantity());
        apples.add(apple);
        return apple;
    }
}

package org.wesome.graphql;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

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

directive @NotEmpty(message : String = "graphql.validation.NotEmpty.message") on ARGUMENT_DEFINITION | INPUT_FIELD_DEFINITION
# Apple Object
type Apple{
    # appleId
    appleId:ID!
    # apple Name
    appleName:String
    # apple AppleTaste
    quantity:Int
}
# Apple Input Object
input AppleVO{
    # apple Name
    appleName:String @NotEmpty
    # apple quantity
    quantity:Int
}
# Apple Query
type Query{
    # query to get Apple
    findAllApple:[Apple]
}
# Apple Mutation
type Mutation{
    # mutation to add an apple
    addApple(appleVO:AppleVO):Apple
}

\src\main\resources\application.properties

spring.graphql.graphiql.enabled=true

\src\main\resources\ValidationMessages.properties

graphql.validation.NotEmpty.message={path} must not be empty

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>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-graphql</artifactId>
        </dependency>
        <dependency>
            <groupId>com.github.javafaker</groupId>
            <artifactId>javafaker</artifactId>
            <version>1.0.2</version>
        </dependency>
        <dependency>
            <groupId>com.graphql-java</groupId>
            <artifactId>graphql-java-extended-validation</artifactId>
            <version>21.0</version>
        </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>
    <name>spring boot graphql</name>
    <description>implementing graphql in spring boot</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

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

mutation AddApple {
    addApple(appleVO: { quantity: 1, appleName: "" }) {
        appleId
        appleName
        quantity
    }
}