GraphQL APIs with Spring Boot · Aula

Autorização com Diretivas e Contexto

Aplique regras de autorização usando diretivas e contexto do GraphQL para controlar o acesso a campos e operações.

Autorização com Diretivas e Contexto é uma aula grátis de GraphQL APIs with Spring Boot no CoddyKit. Esta é a aula 3 de 4. Você pode ler a aula completa abaixo gratuitamente — depois pratica ao vivo no navegador com um editor de código integrado e um tutor de IA 24/7. Faz parte do caminho de aprendizado de GraphQL APIs with Spring Boot, e seu progresso é sincronizado entre a web e o app CoddyKit. O curso de GraphQL APIs with Spring Boot inclui 4 aulas no total.

Partes desta aula ainda não foram traduzidas e aparecem em inglês.

What is Authorization?

Welcome! In this lesson, we'll dive into authorization, a critical aspect of API security. Authorization determines what an authenticated user is allowed to do or access.

Authentication: Verifies who you are (e.g., username/password).
Authorization: Verifies what you can do (e.g., access admin data).

Without proper authorization, even authenticated users might access sensitive data or perform actions they shouldn't.

Authorization Challenges in GraphQL

GraphQL's flexible nature presents unique authorization challenges compared to traditional REST APIs:

Field-level access: Clients can request specific fields. You might need to restrict access to individual fields within a type.
Nested data: Complex queries can fetch deeply nested data. Authorization checks need to apply throughout the query tree.
Dynamic roles: User roles and permissions can vary, requiring dynamic checks.

We need robust mechanisms to enforce these rules effectively.

Introducing GraphQL Directives

GraphQL directives are powerful features that allow you to extend the schema with custom logic. They are denoted by an @ symbol, like @deprecated or @skip.

Think of them as annotations for your schema. They can be attached to fields, types, arguments, and more, allowing you to add metadata or alter the execution behavior of your GraphQL API.

Custom Directive: @hasRole

We can define our own custom directives for authorization. A common example is an @hasRole directive. This directive would allow you to specify required roles directly in your schema.

Here's how you might define it in your Schema Definition Language (SDL):

directive @hasRole(role: String!) on FIELD_DEFINITION

This declares a directive named hasRole that takes a mandatory role argument (a String) and can only be applied to a FIELD_DEFINITION.

Spring Boot Directive Wiring

To make a custom directive functional in Spring Boot, you need to 'wire' it. This involves implementing the SchemaDirectiveWiring interface from graphql-java.

This wiring class intercepts the schema parsing process and allows you to modify how fields or types behave when your directive is encountered. It's where you'll inject your authorization logic.

Implementing Directive Logic

Inside your SchemaDirectiveWiring implementation, you'll override methods like onField. When the GraphQL engine processes a field with your @hasRole directive, this method is called.

Within onField, you can:

Extract the required role from the directive's arguments.
Get the current user's roles from the GraphQL Context.
Compare the roles and, if unauthorized, throw an exception or return null.

GraphQL Context for User Info

The GraphQL Context is a crucial object that accompanies every GraphQL request. It's like a backpack for your request, carrying request-scoped data that resolvers and directive wirings can access.

For authorization, the context is where you'll typically store information about the currently authenticated user, such as their ID, username, and crucially, their roles or permissions.

Integrating User Context (Runnable)

Here's a minimal Spring Boot app demonstrating how to inject user roles into the GraphQLContext. This context can then be accessed by your resolvers and directive wirings.

Try running this and querying myRoles to see the injected roles.

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import graphql.kickstart.tools.GraphQLQueryResolver;
import graphql.schema.GraphQLContext;
import graphql.kickstart.servlet.context.GraphQLServletContextBuilder;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.websocket.Session;
import javax.websocket.server.HandshakeRequest;
import java.util.Arrays;
import java.util.List;
import java.util.HashMap;
import java.util.Map;

@SpringBootApplication
public class ContextDemoApp {

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

    // Resolver to show context access
    @Bean
    public GraphQLQueryResolver queryResolver() {
        return new GraphQLQueryResolver() {
            public List<String> myRoles(GraphQLContext context) {
                Map<String, Object> user = context.get("user");
                if (user != null && user.containsKey("roles")) {
                    return (List<String>) user.get("roles");
                } 
                return Arrays.asList("GUEST");
            }
        };
    }

    // Custom GraphQLContextBuilder to inject user data
    @Bean
    public GraphQLServletContextBuilder graphQLServletContextBuilder() {
        return new GraphQLServletContextBuilder() {
            @Override
            public GraphQLContext build(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) {
                Map<String, Object> user = new HashMap<>();
                user.put("id", "user123");
                user.put("name", "Coddy");
                user.put("roles", Arrays.asList("USER", "EDITOR")); // Mock roles
                GraphQLContext context = GraphQLContext.newContext().build();
                context.put("user", user); // Add user to context
                return context;
            }

            @Override
            public GraphQLContext build(Session session, HandshakeRequest handshakeRequest) {
                // Not used in typical HTTP requests, but required for interface
                return GraphQLContext.newContext().build();
            }
        };
    }
}

Applying Directives in Schema

Once your @hasRole directive is defined and wired up, you can apply it directly to your schema fields. This makes authorization rules declarative and easy to see.

For example, to restrict a field called adminDashboard to users with the ADMIN role:

type Query {
  myRoles: [String]
  adminDashboard: String @hasRole(role: "ADMIN")
}

Now, any attempt to query adminDashboard will trigger your directive's logic, which checks the user's roles from the context.

Authorization Flow: Directive + Context

Let's put it all together. When a client queries a field like adminDashboard:

The Spring Boot GraphQL runtime receives the request.
The GraphQLContextBuilder populates the GraphQLContext with the authenticated user's details, including roles (as shown in the runnable example).
The @hasRole directive wiring intercepts the adminDashboard field.
Inside the directive's logic, it retrieves the required role ("ADMIN") from the directive arguments and the user's roles from the GraphQLContext.
If the user has the required role, the query proceeds to the field's data resolver. Otherwise, an authorization error is returned.

Check Your Understanding

Which of the following best describes the primary purpose of the GraphQL Context in the context of authorization?

Recap: Directives & Context

You've learned how to implement robust authorization in GraphQL with Spring Boot!

Authorization controls what an authenticated user can access.
GraphQL Directives extend schema behavior, allowing declarative authorization rules like @hasRole.
The GraphQL Context is essential for carrying dynamic, request-scoped user information (like roles) to enable these authorization checks.

By combining directives and context, you can build secure and flexible GraphQL APIs.

Perguntas Frequentes

A aula “Autorização com Diretivas e Contexto” é grátis?

Sim — o texto completo de “Autorização com Diretivas e Contexto” é grátis para ler aqui na web. Para praticá-la interativamente (um editor de código integrado e um tutor de IA 24/7) e desbloquear o restante do curso de GraphQL APIs with Spring Boot, atualize para CoddyKit PRO. O curso de GraphQL APIs with Spring Boot inclui 4 aulas no total.

O que vou aprender em “Autorização com Diretivas e Contexto”?

Aplique regras de autorização usando diretivas e contexto do GraphQL para controlar o acesso a campos e operações. Você pratica GraphQL APIs with Spring Boot com código prático que executa diretamente no navegador, e um tutor de IA 24/7 responde suas dúvidas enquanto trabalha na aula.

Preciso ter experiência prévia para começar GraphQL APIs with Spring Boot?

Nenhuma experiência prévia é necessária. GraphQL APIs with Spring Boot no CoddyKit é estruturado para alunos iniciantes até avançados, então você pode começar aqui ou desde o início e aprender no seu ritmo. Esta é a aula 3 de 4.

Quanto tempo leva a aula “Autorização com Diretivas e Contexto”?

A maioria das aulas CoddyKit leva cerca de 5–10 minutos. Cada uma é compacta e interativa, então você faz progresso constante e retoma exatamente de onde parou entre web e app.

Posso escrever e executar código nesta aula de GraphQL APIs with Spring Boot?

Sim. Cada aula de GraphQL APIs with Spring Boot inclui um editor de código integrado, então você escreve e executa código real direto no navegador e recebe feedback de IA instantaneamente — nenhuma configuração local necessária.

Todas as aulas deste curso

Tratamento Personalizado de Erros no GraphQL
Autenticação com Spring Security
Autorização com Diretivas e Contexto
Limitação de taxa e proteção contra profundidade de consultas

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