GraphQL and Spring Boot 2.0.3

Question

I want to test GraphQL for a future project. The project will use Spring Boot, Spring Security, and GraphQL. So I created a new Spring Boot App in IntelliJ using the build in Spring Initializr. The Spring Boot version is, of course, the latest (2.0.3.RELEASE) Now I add the dependencies for GraphQL and GraphiQL.

<dependency>
    <groupId>com.graphql-java</groupId>
    <artifactId>graphql-spring-boot-starter</artifactId>
    <version>4.3.0</version>
</dependency>
<dependency>
    <groupId>com.graphql-java</groupId>
    <artifactId>graphql-java-tools</artifactId>
    <version>5.2.0</version>
</dependency>
<dependency>
    <groupId>com.graphql-java</groupId>
    <artifactId>graphiql-spring-boot-starter</artifactId>
    <version>4.3.0</version>
</dependency>

To test this, I ran the application but there was no /graphql endpoint. In this case, I configured it in application.properties without a problem:

# GraphQL
graphql.servlet.mapping=/graphql
graphql.servlet.enabled=true
graphql.servlet.corsEnabled=true
# GraphiQL
graphiql.mapping=/graphiql
graphiql.endpoint=/graphql
graphiql.enabled=true
graphiql.cdn.enabled=true
graphiql.cdn.version=0.11.11

After testing again, the endpoint is there, so now I could write a schema, resolvers and so on. This is what I implemented:

Schema:

schema {
    query: Query
    mutation: Mutation
}

type Greeting {
    id: ID!
    message: String!
}

type Query {
    greetingsAll: [Greeting]
}

type Mutation {
    greeting(message: String!): Greeting
}

Model:

@NoArgsConstructor
@AllArgsConstructor
@Getter
@Setter
@Builder
@ToString
@Entity
public class Greeting {
    @Id
    @GeneratedValue
    private Long id;
    private String message;
}

Repository

@Repository
public interface GreetingRepository extends JpaRepository<Greeting, Long> {
}

QueryResolver

@Component
public class QueryResolver implements GraphQLQueryResolver {

    @Autowired
    private GreetingRepository greetingRepository;

    public Greeting greeting(Long id) {
        return greetingRepository.getOne(id);
    }

    public Iterable<Greeting> getGreetingsAll() {
        return greetingRepository.findAll();
    }
}

MutationResolver

@Component
public class MutationResolver implements GraphQLMutationResolver {

    @Autowired
    private GreetingRepository greetingRepository;

    public Greeting newGreeting(String message) {
        Greeting greeting = new Greeting();
        greeting.setMessage(message);

        return greetingRepository.save(greeting);
    }
}

Beans for SpringBoot

@SpringBootApplication
public class GraphqlApplication {

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

    @Bean
    ApplicationRunner init(GreetingRepository greetingRepository) {
        return args -> {
            Stream.of("Hallo", "Guten Tag", "Moin").forEach(greeting -> greetingRepository.save(Greeting.builder().message(greeting).build()));
            greetingRepository.findAll().forEach(System.out::println);
        };
    }

    @Bean
    public QueryResolver query() {
        return new QueryResolver();
    }

    @Bean
    public MutationResolver mutation() {
        return new MutationResolver();
    }
}

While trying to test the application again to see if I could run a query using GraphiQL, the application wouldn't start:

org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:155) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:544) ~[spring-context-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:759) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:395) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:327) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1255) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1243) [spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at de.eno.prototyp.graphql.GraphqlApplication.main(GraphqlApplication.java:14) [classes/:na]
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
    at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:86) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:413) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:174) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:179) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:152) ~[spring-boot-2.0.3.RELEASE.jar:2.0.3.RELEASE]
    ... 8 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLServletRegistrationBean' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLServletRegistrationBean' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLServlet' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLServlet' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchemaProvider' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchemaProvider' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchema' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchema' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schemaParser' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) 
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLServlet' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLServlet' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchemaProvider' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchemaProvider' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchema' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchema' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schemaParser' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    ... 24 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchemaProvider' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLWebAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchemaProvider' parameter 0; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchema' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchema' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schemaParser' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    ... 38 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'graphQLSchema' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Unsatisfied dependency expressed through method 'graphQLSchema' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schemaParser' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:732) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:474) 
    ... 52 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'schemaParser' defined in class path resource [com/oembedler/moon/graphql/boot/GraphQLJavaToolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:590) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1256) 
    ... 66 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [com.coxautodev.graphql.tools.SchemaParser]: Factory method 'schemaParser' threw exception; nested exception is com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:582) ~[spring-beans-5.0.7.RELEASE.jar:5.0.7.RELEASE]
    ... 79 common frames omitted
Caused by: com.coxautodev.graphql.tools.FieldResolverError: Found more than one matching resolver for field 'FieldDefinition{name='greetingsAll', type=ListType{type=TypeName{name='Greeting'}}, inputValueDefinitions=[], directives=[]}': [MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}, MethodFieldResolver{method=public java.lang.Iterable de.eno.prototyp.graphql.QueryResolver.getGreetingsAll()}]
    at com.coxautodev.graphql.tools.FieldResolverScanner.findFieldResolver(FieldResolverScanner.kt:39) ~[graphql-java-tools-5.2.0.jar:na]
    at com.coxautodev.graphql.tools.SchemaClassScanner.scanResolverInfoForPotentialMatches(SchemaClassScanner.kt:227) ~[graphql-java-tools-5.2.0.jar:na]
    at com.coxautodev.graphql.tools.SchemaClassScanner.handleRootType(SchemaClassScanner.kt:122) ~[graphql-java-tools-5.2.0.jar:na]
    at com.coxautodev.graphql.tools.SchemaClassScanner.scanForClasses(SchemaClassScanner.kt:80) ~[graphql-java-tools-5.2.0.jar:na]
    at com.coxautodev.graphql.tools.SchemaParserBuilder.scan(SchemaParserBuilder.kt:150) ~[graphql-java-tools-5.2.0.jar:na]
    at com.coxautodev.graphql.tools.SchemaParserBuilder.build(SchemaParserBuilder.kt:156) ~[graphql-java-tools-5.2.0.jar:na]
    at com.oembedler.moon.graphql.boot.GraphQLJavaToolsAutoConfiguration.schemaParser(GraphQLJavaToolsAutoConfiguration.java:65) ~[graphql-spring-boot-autoconfigure-4.3.0.jar:na]

So I don't know what happened but I think GraphQL can not map the Query type to the QueryResolver. But why?

When checking the internet, I read that Spring Boot Version is the reason. So I tested it with Spring Boot 1.5.8.RELEASE, without result.

However, when using an older GraphQL version (4.3.0 and 5.2.0) with Spring boot 1.5.8, it did seem to work fine. So then I tried to use these older GraphQL versions with the new Spring boot version, but then I get another exception:

2018-07-13 14:45:57.666  INFO 12872 --- [io-8080-exec-10] graphql.servlet.GraphQLServlet           : Bad POST request: parsing failed

java.lang.IllegalStateException: Unable to process parts as no multi-part configuration has been provided
    at org.apache.catalina.connector.Request.parseParts(Request.java:2826) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
    at org.apache.catalina.connector.Request.getParts(Request.java:2793) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
    at org.apache.catalina.connector.RequestFacade.getParts(RequestFacade.java:1084) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
    at graphql.servlet.GraphQLServlet.lambda$new$2(GraphQLServlet.java:129) ~[graphql-java-servlet-5.1.0.jar:na]
    at graphql.servlet.GraphQLServlet.doRequest(GraphQLServlet.java:260) ~[graphql-java-servlet-5.1.0.jar:na]
    at graphql.servlet.GraphQLServlet.doPost(GraphQLServlet.java:278) ~[graphql-java-servlet-5.1.0.jar:na]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.31.jar:8.5.31]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

Now I'm really screwed up because of this incompatibility. I want to use the new versions of all libraries. Does anybody have a solution?

Answer 1

You're creating your resolver beans twice. Both your MutationResolver and QueryResolver are annotated with @Component, which means that Spring will create an instance and register it. However, within the GraphqlApplication you also created beans for both resolvers using the @Bean annotation.

This causes an issue, because the GraphQL library will look for a proper resolver for greetingsAll, but it will find two resolvers due to your bean being mapped twice.

The solution is to either remove the @Component annotation, or to remove the following bean configuration:

@Bean
public QueryResolver query() {
    return new QueryResolver();
}

@Bean
public MutationResolver mutation() {
    return new MutationResolver();
}