Basic to Advanced, Complete GraphQL Java with Spring boot 3

Discover how GraphQL, a strongly typed API query language, fetches exact data via a single endpoint and avoids unnecessary data, using query, mutation, and subscription, with subscriptions leveraging websockets.

Build and run a spring boot graphql app to write and map your first graphql query, create a schema, test with altair, and use variables and not null arguments.

Learn to design a realistic GraphQL API with a MySQL-backed student management system, creating JPA entities, repositories, and Spring Boot configurations to enable CRUD operations.

Develop a GraphQL API to fetch all students and their subject marks, define student response and student subject response types, and implement a schema-mapped resolver to avoid overfetching.

discover how GraphQL data loader batching solves the n+1 problem by batching student results into a single call and using batch mapping with Spring Boot GraphQL annotations.

Learn how GraphQL interfaces and fragments power a unified get members query in a Spring Boot 3 app, with data loader batching for teachers and students.

Explore GraphQL unions and interfaces, compare differences, and learn when to use each with a search example returning student or teacher subject responses.

Learn how GraphQL batches multiple queries in parallel within one request to boost performance. Use field aliases to combine search and all members into a single network call.

Explore GraphQL extended scalars in Spring Boot three to add BigDecimal via runtime wiring, and build a custom email scalar with regex and alias id as key.

Explore GraphQL directives, from built-in skip, include, and deprecated to custom uppercase directives, and implement them with Spring Boot to manipulate field data.

Learn to implement GraphQL pagination in Spring Boot 3 using offset and limit and the GraphQL cursor connection (Relay) with edges, nodes, and page info, including after and before cursors.

Explore GraphQL mutation for inserting, updating, and deleting data using member input and a status response in a Spring Boot 3 GraphQL Java setup.

Learn to handle GraphQL exceptions in Spring Boot 3 by implementing local mutation-level error handling and a global controller advice, including validation errors, runtime exceptions, and customizing error responses.

Learn how to implement GraphQL request and response interceptors in Spring Boot, pass header data through the GraphQL context, and access or expose headers using the data fetching environment.

Learn GraphQL subscription and event-based notifications using WebSocket and Spring Boot, building a real-time member update flow with a flux sink and publisher.

In GraphQL subscription (part II) learn to generalize a member subscription by wiring a generalized member publisher, emitting add and remove member events to a WebSocket subscription for real-time notifications.

Master GraphQL test design with JUnit and Spring Boot, using a GraphQL tester and web client to validate queries, mutations, and subscriptions through unit and integration tests.

Write GraphQL mutation test cases for adding and removing a member using the Altair client, validating status and created member id, with cleanup and nested path assertions.

Craft and validate GraphQL subscription test cases using a web socket tester in a Spring Boot setup, verifying member created and member removed events via reactor http client.

Explore testing GraphQL error handling in Java with Spring Boot 3, covering integration test cases for missing headers, GraphQL errors, and validation errors, and learn how to assert error details.

Explore building reactive GraphQL APIs with Spring Web Flux, enabling query, mutation, and subscription over a native reactive server and WebSocket, backed by MongoDB.

Set up a reactive GraphQL project with spring boot 3, configure webflux, spring graphql, and reactive mongo dependencies, and scaffold controller, entity, service, and repository for query, mutation, and subscription.

Implement a reactive GraphQL query and mutation in Spring Boot 3 with a reactive MongoDB repository, defining a student schema and using Flux and Mono.

Implement a reactive GraphQL subscription in Spring Boot using WebFlux, with a sink and multicast to publish student updates over GraphQL over WebSocket.

Set up GraphQL over RSocket in a Spring Boot 3 project by enabling reactive circuit, configuring the RSocket port and mapping, and testing with an RSocket client.

Learn to test GraphQL APIs from the command line using curl, including building data payloads with query, operation name, and variables, and validating results via a socket client.

Learn to test GraphQL operations, including queries, mutations, and subscriptions, using Rsocket, with hands-on guidance on building requests, operation names, variables, and inter-service messaging in PowerShell.