BAEL-3007: WebClient vs RestTemplate example.

pom.xml

@@ -606,6 +606,7 @@
 				<module>spring-5-data-reactive</module>
 				<module>spring-5-mvc</module>
 				<module>spring-5-reactive</module>
+				<module>spring-5-reactive-2</module>
 				<module>spring-5-reactive-client</module>
 				<module>spring-5-reactive-oauth</module>
 				<module>spring-5-reactive-security</module>
@@ -820,6 +821,7 @@
 				<module>spring-5</module>
 				<module>spring-5-data-reactive</module>
 				<module>spring-5-reactive</module>
+				<module>spring-5-reactive-2</module>
 				<module>spring-5-reactive-client</module>
 				<module>spring-5-reactive-security</module>
 				<module>spring-5-security</module>
@@ -1277,6 +1279,7 @@
 				<module>spring-5-data-reactive</module>
 				<module>spring-5-mvc</module>
 				<module>spring-5-reactive</module>
+				<module>spring-5-reactive-2</module>
 				<module>spring-5-reactive-client</module>
 				<module>spring-5-reactive-oauth</module>
 				<module>spring-5-reactive-security</module>

spring-5-reactive-2/.gitignore

@@ -0,0 +1,12 @@
+#folders#
+.idea
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

spring-5-reactive-2/README.md

@@ -0,0 +1 @@
+## Spring 5 Reactive Project

spring-5-reactive-2/pom.xml

@@ -0,0 +1,50 @@
+<?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>
+    <groupId>com.baeldung</groupId>
+    <artifactId>spring-5-reactive-2</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <name>spring-5-reactive-2</name>
+    <packaging>jar</packaging>
+    <description>spring 5 sample project about new features</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-2</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-webflux</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <mainClass>com.baeldung.webclient.WebClientApplication</mainClass>
+                    <layout>JAR</layout>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

spring-5-reactive-2/src/main/java/com/baeldung/webclient/Tweet.java

@@ -0,0 +1,13 @@
+package com.baeldung.webclient;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+public class Tweet {
+    private String text;
+    private String username;
+}

spring-5-reactive-2/src/main/java/com/baeldung/webclient/TweetsSlowServiceController.java

@@ -0,0 +1,20 @@
+package com.baeldung.webclient;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Arrays;
+import java.util.List;
+
+@RestController
+public class TweetsSlowServiceController {
+
+    @GetMapping("/slow-service-tweets")
+    private List<Tweet> getAllTweets() throws Exception {
+        Thread.sleep(2000L); // delay
+        return Arrays.asList(
+          new Tweet("RestTemplate rules", "@user1"),
+          new Tweet("WebClient is better", "@user2"),
+          new Tweet("OK, both are useful", "@user1"));
+    }
+}

spring-5-reactive-2/src/main/java/com/baeldung/webclient/WebClientApplication.java

@@ -0,0 +1,11 @@
+package com.baeldung.webclient;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class WebClientApplication {
+    public static void main(String[] args) {
+        SpringApplication.run(WebClientApplication.class, args);
+    }
+}

spring-5-reactive-2/src/main/java/com/baeldung/webclient/WebController.java

@@ -0,0 +1,60 @@
+package com.baeldung.webclient;
+
+import lombok.Setter;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.reactive.function.client.WebClient;
+import reactor.core.publisher.Flux;
+
+import java.util.List;
+
+@Slf4j
+@RestController
+public class WebController {
+
+    private static final int DEFAULT_PORT = 8080;
+
+    @Setter
+    private int serverPort = DEFAULT_PORT;
+
+    @GetMapping("/tweets-blocking")
+    public List<Tweet> getTweetsBlocking() {
+        log.info("Starting BLOCKING Controller!");
+        final String uri = getSlowServiceUri();
+
+        RestTemplate restTemplate = new RestTemplate();
+        ResponseEntity<List<Tweet>> response = restTemplate.exchange(
+          uri, HttpMethod.GET, null,
+          new ParameterizedTypeReference<List<Tweet>>(){});
+
+        List<Tweet> result = response.getBody();
+        result.forEach(tweet -> log.info(tweet.toString()));
+        log.info("Exiting BLOCKING Controller!");
+        return result;
+    }
+
+    @GetMapping(value = "/tweets-non-blocking", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
+    public Flux<Tweet> getTweetsNonBlocking() {
+        log.info("Starting NON-BLOCKING Controller!");
+        Flux<Tweet> tweetFlux = WebClient.create()
+          .get()
+          .uri(getSlowServiceUri())
+          .retrieve()
+          .bodyToFlux(Tweet.class);
+
+        tweetFlux.subscribe(tweet -> log.info(tweet.toString()));
+        log.info("Exiting NON-BLOCKING Controller!");
+        return tweetFlux;
+    }
+
+    private String getSlowServiceUri() {
+        return "http://localhost:" + serverPort + "/slow-service-tweets";
+    }
+
+}

spring-5-reactive-2/src/test/java/com/baeldung/webclient/WebControllerIntegrationTest.java

@@ -0,0 +1,51 @@
+package com.baeldung.webclient;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.web.server.LocalServerPort;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.reactive.server.WebTestClient;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT, classes = WebClientApplication.class)
+public class WebControllerIntegrationTest {
+
+    @LocalServerPort
+    int randomServerPort;
+
+    @Autowired
+    private WebTestClient testClient;
+
+    @Autowired
+    private WebController webController;
+
+    @Before
+    public void setup() {
+        webController.setServerPort(randomServerPort);
+    }
+
+    @Test
+    public void whenEndpointWithBlockingClientIsCalled_thenThreeTweetsAreReceived() {
+        testClient.get()
+          .uri("/tweets-blocking")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBodyList(Tweet.class)
+          .hasSize(3);
+    }
+
+    @Test
+    public void whenEndpointWithNonBlockingClientIsCalled_thenThreeTweetsAreReceived() {
+        testClient.get()
+          .uri("/tweets-non-blocking")
+          .exchange()
+          .expectStatus()
+          .isOk()
+          .expectBodyList(Tweet.class)
+          .hasSize(3);
+    }
+}