webflux tutorial

Author: ErwanLT

pom.xml

@@ -45,6 +45,7 @@
         <module>bucket4j-tutorial</module>
 		<module>aspect-tutorial</module>
         <module>messaging-tutorial</module>
+        <module>reactive-tutorial</module>
     </modules>
 	<scm>
 		<url>https://github.com/ErwanLT/springboot-demo.git</url>

reactive-tutorial/pom.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>fr.eletutour</groupId>
+        <artifactId>springboot-demo</artifactId>
+        <version>6.0.1-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>reactive-tutorial</artifactId>
+
+    <properties>
+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+    </dependencies>
+
+</project>

reactive-tutorial/src/main/java/fr/eletutour/reactive/ReactiveTutorialApplication.java

@@ -0,0 +1,11 @@
+package fr.eletutour.reactive;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class ReactiveTutorialApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(ReactiveTutorialApplication.class);
+    }
+}

reactive-tutorial/src/main/java/fr/eletutour/reactive/controller/ReactiveController.java

@@ -0,0 +1,63 @@
+package fr.eletutour.reactive.controller;
+
+import fr.eletutour.reactive.model.Post;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.server.ResponseStatusException;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.core.scheduler.Schedulers;
+
+
+@RestController
+@RequestMapping("/api")
+public class ReactiveController {
+
+    private final WebClient webClient = WebClient.create("https://jsonplaceholder.typicode.com");
+
+    @GetMapping("/posts/{id}")
+    public Mono<Post> getPost(@PathVariable String id) {
+        return webClient.get()
+                .uri("/posts/{id}", id)
+                .retrieve()
+                .onStatus(HttpStatusCode::isError, response -> Mono.error(new ResponseStatusException(response.statusCode(), "API call failed")))
+                .bodyToMono(Post.class);
+    }
+
+    @GetMapping("/posts")
+    public Flux<Post> getPosts() {
+        return webClient.get()
+                .uri("/posts")
+                .retrieve()
+                .onStatus(HttpStatusCode::isError, response -> Mono.error(new ResponseStatusException(response.statusCode(), "API call failed")))
+                .bodyToFlux(Post.class);
+    }
+
+
+    @GetMapping("/posts/{id}/enriched")
+    public Mono<Post> getEnrichedPost(@PathVariable String id) {
+        return getPost(id)
+                .flatMap(post -> Mono.fromCallable(() -> enrichPostBlocking(post))
+                        .subscribeOn(Schedulers.boundedElastic())
+                );
+    }
+
+
+    private Post enrichPostBlocking(Post post) {
+        try {
+            Thread.sleep(1000);
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+        }
+        return new Post(
+                post.userId(),
+                post.id(),
+                "[Enriched] " + post.title(),
+                post.body()
+        );
+    }
+}

reactive-tutorial/src/main/java/fr/eletutour/reactive/model/Post.java

@@ -0,0 +1,4 @@
+package fr.eletutour.reactive.model;
+
+public record Post(Integer userId, Integer id, String title, String body) {
+}