HTTP Clients and Services Demo Suite

A multi-module Maven workspace showing several ways to call HTTP APIs with modern Spring on Java 25 and Spring Boot 4.1.0.

Modules at a glance

Module	Port	What it does
rest-service	8080	Employee REST API backed by Spring MVC, JPA, cache abstraction, and H2
rest-client	8081	Synchronous Spring RestClient façade plus a small Spring Cloud Config refresh demo
web-client	8082	Reactive WebClient client with SSL settings and Resilience4j circuit breaker + retry
graphql-service	9090	GraphQL server exposing movie and actor queries plus an add-movie mutation
graphql-client	9091	GraphQL consumer that wraps HttpGraphQlClient behind simple REST endpoints

Tech baseline

• Java 25
• Spring Boot 4.1.0
• Spring Cloud 2025.1.2
• Maven multi-module build
• Lombok 1.18.46

Project structure

http-clients/
├── rest-service/
├── rest-client/
├── web-client/
├── graphql-service/
└── graphql-client/

Build everything

Run from the repository root:

mvn test

To package all modules:

mvn clean package

Recommended local run order

1. Start rest-service
2. Start graphql-service
3. Start rest-client, web-client, and/or graphql-client

Run a single module

Each module includes its own Maven wrapper, so you can run them independently:

cd rest-service && ./mvnw spring-boot:run
cd graphql-service && ./mvnw spring-boot:run
cd rest-client && ./mvnw spring-boot:run
cd web-client && ./mvnw spring-boot:run
cd graphql-client && ./mvnw spring-boot:run

Quick smoke tests

REST service

curl http://localhost:8080/rest/employees/all
curl http://localhost:8080/rest/employees/1

WebClient façade

curl http://localhost:8082/webclient/get-all-employee
curl http://localhost:8082/webclient/get-employee/1

RestClient façade

curl http://localhost:8081/client/employees
curl http://localhost:8081/client/employees/1

GraphQL service

curl http://localhost:9090/graphql \
  -H 'Content-Type: application/json' \
  -d '{"query":"{ movies { id title year director } }"}'

GraphQL client façade

curl http://localhost:9091/get-all-movies
curl -X POST http://localhost:9091/add-movie \
  -H 'Content-Type: application/json' \
  -d '{"id":6,"title":"Dark Knight","year":2010,"genres":["Action","SciFi"],"director":"Christopher Nolan"}'

Where to look next

• rest-service/README.md
• rest-client/README.md
• web-client/README.md
• graphql-service/README.md
• graphql-client/ReadMe.md