Spring Boot Library for Mediator pattern

Main Purpose

This Spring Boot library provide an implementation for the behavioral pattern Mediator.

Getting Started

The library is a Maven Artifact published on GitHub Package Registry. Check the package versions list here.

Dependency

The library version dependency should be declared on pom.xml file.

<dependency>
  <groupId>io.github.josephrodriguez</groupId>
  <artifactId>mediator-spring-boot-starter</artifactId>
  <version>1.1.0</version>
</dependency>

Install

Install the package with Maven running the command line.

$ mvn install

Usage

Annotation

Auto-configuration feature is supported by the library using the annotation @EnableMediator annotation in the Spring Boot Application.

import io.github.josephrodriguez.annotations.EnableMediator;

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

Request

Lets define the class that

EchoRequest.java

@AllArgsConstructor
public class EchoRequest implements Request<EchoResponse> {
    private final String message;
}

Response

EchoResponse.java

@Data
@AllArgsConstructor
public class EchoResponse {
    private final String message;
}

Handler

Implement the RequestHandler interfaces to handle the request object.

EchoRequestHandler.java

import io.github.josephrodriguez.interfaces.RequestHandler;

@Service
public class EchoRequestHandler implements RequestHandler<EchoRequest, EchoResponse> {

    @Override
    public EchoResponse handle(EchoRequest request) {
        return new EchoResponse(request.getMessage());
    }
}

Mediator in action

Use the Mediator service with dependency injection.

import io.github.josephrodriguez.Mediator;

@RestController
public class EchoController {

    private Mediator mediator;

    public EchoController(Mediator mediator) {
        this.mediator = mediator;
    }

    @RequestMapping("/echo")
    public ResponseEntity<EchoResponse> echo() throws UnsupportedRequestException {

        EchoRequest request = new EchoRequest(UUID.randomUUID().toString());
        EchoResponse response = mediator.send(request);

        return ResponseEntity
                .ok()
                .body(response);
    }
}

Asynchronous support

Asynchronous operations are supported using the CompletableFuture<?> class.

EchoRequest request = new EchoRequest("Hi Mediator");
CompletableFuture<EchoResponse> future = mediator.sendAsync(request);
EchoResponse response = response.join();

DateTimeEvent event = new DateTimeEvent();
CompletableFuture<Void> future = mediator.publishAsync(event);