Bean of type 'org.springframework.web.reactive.function.client.WebClient' that could not be found - spring-boot

Question

I'm studying push notifications using the example of this manual https://golb.hplar.ch/2018/01/Sending-Web-push-messages-from-Spring-Boot-to-Browsers.html.
I am faced with the problem that when I run the application, I get the error
Parameter 1 of constructor in ru.stepanb.MetricPushingApplication.push.PushChuckJokeService required could not be found.
Consider defining a bean of type 'org.springframework.web.reactive.function.client.WebClient' in your configuration. "
.
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;
#Service
public class PushChuckJokeService {
private final FcmClient fcmClient;
private final WebClient webClient;
private int seq = 0;
public PushChuckJokeService(FcmClient fcmClient, WebClient webClient) {
this.fcmClient = fcmClient;
this.webClient = webClient;
}
#Scheduled(fixedDelay = 30_000)
public void sendChuckQuotes() {
IcndbJoke joke =
this.webClient.get().uri("http://api.icndb.com/jokes/random")
.retrieve().bodyToMono(IcndbJoke.class).block();
try {
sendPushMessage(joke);
}
catch (InterruptedException | ExecutionException e) {
//Application.logger.error("send chuck joke", e);
}
}
void sendPushMessage(IcndbJoke joke) throws InterruptedException,
ExecutionException {
Map<String, String> data = new HashMap<>();
data.put("id", String.valueOf(joke.getValue().getId()));
data.put("joke", joke.getValue().getJoke());
data.put("seq", String.valueOf(this.seq++));
data.put("ts", String.valueOf(System.currentTimeMillis()));
System.out.println("Sending chuck joke...");
this.fcmClient.send(data);
}
}
Here is my pom.xml file
<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>ru.stepanb</groupId>
<artifactId>MetricPushingApplication</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>MetricPushingApplication</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.5.RELEASE</version>
<relativePath />
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
<dependency>
<groupId>com.google.firebase</groupId>
<artifactId>firebase-admin</artifactId>
<version>6.8.1</version>
<exclusions>
<exclusion>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.http-client</groupId>
<artifactId>google-http-client-jackson</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.http-client</groupId>
<artifactId>google-http-client-gson</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.api-client</groupId>
<artifactId>google-api-client-gson</artifactId>
</exclusion>
<exclusion>
<groupId>joda-time</groupId>
<artifactId>joda-time</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.auto.value</groupId>
<artifactId>auto-value</artifactId>
</exclusion>
<exclusion>
<groupId>org.threeten</groupId>
<artifactId>threetenbp</artifactId>
</exclusion>
<exclusion>
<groupId>org.json</groupId>
<artifactId>json</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-firestore</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.apis</groupId>
<artifactId>google-api-services-storage</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
</exclusion>
<exclusion>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpcore</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.api</groupId>
<artifactId>gax</artifactId>
</exclusion>
<exclusion>
<groupId>com.google.cloud</groupId>
<artifactId>google-cloud-storage</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>com.google.code.findbugs</groupId>
<artifactId>jsr305</artifactId>
<version>3.0.2</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<debug>true</debug>
<parameters>true</parameters>
<annotationProcessorPaths>
<path>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<version>2.1.5.RELEASE</version>
</path>
</annotationProcessorPaths>
</configuration>
</plugin>
</plugins>
</build>
And my controller
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestController;
import reactor.core.publisher.Mono;
#RestController
#CrossOrigin
public class RegistryController {
private final FcmClient fcmClient;
public RegistryController(FcmClient fcmClient) {
this.fcmClient = fcmClient;
}
#PostMapping("/register")
#ResponseStatus(HttpStatus.NO_CONTENT)
public Mono<Void> register(#RequestBody Mono<String> token) {
return token.doOnNext(t -> this.fcmClient.subscribe("chuck", t)).then();
}
}
Could you also explain to me how the creation of a WebClient occurs at all when Spring application is created by this line?
SpringApplication.run(MetricPushingApplication.class, args);

Answer 1

There is no WebClient registered as bean.
You can simply use it like this:
WebClient.create().get().uri("http://api.icndb.com/jokes/random")
.retrieve().bodyToMono(IcndbJoke.class).block();
Or you use it like described in the Spring Boot Reference Manual
#Service
public class MyService {
private final WebClient webClient;
public MyService(WebClient.Builder webClientBuilder) {
this.webClient = webClientBuilder.baseUrl("https://example.org").build();
}
public Mono<Details> someRestCall(String name) {
return this.webClient.get().uri("/{name}/details", name)
.retrieve().bodyToMono(Details.class);
}
}
See: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#io.rest-client.webclient

Answer 2

You should config the bean in the Configuration Class. For example:
#Configuration
class Configuration{
#Bean
WebClient webClient(WebClient.Builder builder) {
return builder.build();
}
}
And then you could use the webClient dependency in other class. For Example:
class otherClass{
private WebClient client;
//Your use
}

Answer 3

You should update the dependency to resolve the issue of 'org.springframework.web.reactive.function.client.WebClient' that could not be found
compile 'org.springframework.boot:spring-boot-starter-webflux:2.6.1'
Please see this answer already posted.