Welcome message on default url

Author: ZNevzz

src/main/java/spring/znevzz/reactive/bean/ICacheRequest.java

@@ -0,0 +1,8 @@
+package spring.znevzz.reactive.bean;
+
+import reactor.core.publisher.Mono;
+
+public interface ICacheRequest<T> {
+    String getUser();
+    T getPayload();
+}

src/main/java/spring/znevzz/reactive/bean/ICacheResponse.java

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+package spring.znevzz.reactive.bean;
+
+import java.time.LocalDate;
+import java.util.Optional;
+
+public interface ICacheResponse<R> {
+    LocalDate getLastUpdated();
+    Optional<R> getPayload();
+}

src/main/java/spring/znevzz/reactive/bean/SimpleCacheRequest.java

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+package spring.znevzz.reactive.bean;
+
+import lombok.Data;
+
+@Data
+public class SimpleCacheRequest implements ICacheRequest<String> {
+
+    private String user;
+    private String payload;
+
+    @Override
+    public String getUser() {
+        return "";
+    }
+
+    @Override
+    public String getPayload() {
+        return this.payload;
+    }
+}

src/main/java/spring/znevzz/reactive/bean/SimpleCacheResponse.java

@@ -0,0 +1,24 @@
+package spring.znevzz.reactive.bean;
+
+import lombok.Data;
+
+import java.time.LocalDate;
+import java.util.Optional;
+
+@Data
+public class SimpleCacheResponse implements ICacheResponse<String> {
+
+    private String payload;
+
+    @Override
+    public LocalDate getLastUpdated() {
+        return LocalDate.now();
+    }
+
+    @Override
+    public Optional<String> getPayload() {
+        return Optional.ofNullable(payload);
+    }
+
+
+}

src/main/java/spring/znevzz/reactive/handler/CacheRequestHandler.java

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+package spring.znevzz.reactive.handler;
+
+import org.springframework.stereotype.Component;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import spring.znevzz.reactive.bean.ICacheRequest;
+import spring.znevzz.reactive.bean.ICacheResponse;
+
+@Component
+public class CacheRequestHandler implements IRequestHandler<ICacheRequest, ICacheResponse> {
+
+    @Override
+    public Flux<ICacheResponse> get(ICacheRequest iCacheRequest) {
+        return Flux.empty();
+    }
+
+    @Override
+    public Mono handle(ServerRequest serverRequest) {
+        return Mono.empty();
+    }
+}

src/main/java/spring/znevzz/reactive/handler/IRequestHandler.java

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+package spring.znevzz.reactive.handler;
+
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
+import org.springframework.web.reactive.function.server.HandlerFunction;
+import org.springframework.web.reactive.function.server.ServerRequest;
+import org.springframework.web.reactive.function.server.ServerResponse;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+
+import static org.springframework.web.reactive.function.server.ServerResponse.ok;
+
+public interface  IRequestHandler<T,R> extends HandlerFunction {
+
+    Flux<R> get(T t);
+
+    default <T extends ServerResponse> Mono<T> welcome(ServerRequest serverRequest) {
+        Mono welcomeMessage = Mono.empty();
+        Mono<String> responseMessage = Mono.just("welcome");
+        welcomeMessage = ok()
+                .hint("key", "value")
+                .body(responseMessage, String.class)
+                ;
+        return welcomeMessage;
+    }
+}

src/main/java/spring/znevzz/reactive/router/CacheRouter.java

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+package spring.znevzz.reactive.router;
+
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.reactive.function.server.RouterFunction;
+import org.springframework.web.reactive.function.server.RouterFunctions;
+import spring.znevzz.reactive.handler.IRequestHandler;
+
+import static org.springframework.http.MediaType.APPLICATION_JSON;
+import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
+import static org.springframework.web.reactive.function.server.RequestPredicates.accept;
+
+/**
+ * more information at:
+ * - https://spring.io/blog/2016/09/22/new-in-spring-5-functional-web-framework
+ * - https://dzone.com/articles/creating-multiple-routerfunctions-in-spring-webflux
+ */
+
+@Configuration
+public class CacheRouter {
+    @Bean
+    public RouterFunction routers(IRequestHandler handler) {
+        return RouterFunctions.route(
+                GET("/")
+                .and(accept(APPLICATION_JSON)),
+                handler::welcome);
+    }
+}

src/main/resources/application.properties

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+spring:
+  application:
+    name: spring-caching-app
+server:
+  port: 10001