此版本仍在开发中，尚未被视为稳定版本。对于最新的稳定版本，请使用 Spring Boot 3.4.3！spring-doc.cadn.net.cn

调用 REST 服务

Spring Boot 提供了多种便捷的方法来调用远程 REST 服务。如果您正在开发一个非阻塞响应式应用程序并且您正在使用 Spring WebFlux，那么您可以使用WebClient. 如果您更喜欢阻止 API，则可以使用RestClient或RestTemplate.spring-doc.cadn.net.cn

Web客户端

如果你的 Classpath 中有 Spring WebFlux，我们建议你使用WebClient调用远程 REST 服务。这WebClientinterface 提供了一个函数式风格的 API，并且是完全响应式的。您可以详细了解WebClient在 Spring Framework 文档的 dedicated 部分。spring-doc.cadn.net.cn

如果你不编写反应式 Spring WebFlux 应用程序，你可以使用RestClient而不是WebClient. 这提供了类似的功能 API，但 this is blocking instead reactor 。

Spring Boot 创建并预配置原型WebClient.BuilderBean 为你。强烈建议将它注入到您的组件中，并使用它来创建WebClient实例。 Spring Boot 正在配置该构建器以共享 HTTP 资源并以与服务器相同的方式反映编解码器设置（参见 WebFlux HTTP 编解码器自动配置）等等。spring-doc.cadn.net.cn

以下代码显示了一个典型的示例：spring-doc.cadn.net.cn

Javaspring-doc.cadn.net.cn
Kotlinspring-doc.cadn.net.cn

import reactor.core.publisher.Mono;

import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;

@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);
	}

}





import org.springframework.stereotype.Service
import org.springframework.web.reactive.function.client.WebClient
import reactor.core.publisher.Mono

@Service
class MyService(webClientBuilder: WebClient.Builder) {

	private val webClient: WebClient

	init {
		webClient = webClientBuilder.baseUrl("https://example.org").build()
	}

	fun someRestCall(name: String?): Mono<Details> {
		return webClient.get().uri("/{name}/details", name)
				.retrieve().bodyToMono(Details::class.java)
	}

}



WebClient Runtime

Spring Boot will auto-detect which ClientHttpConnector to use to drive WebClient depending on the libraries available on the application classpath.
In order of preference, the following clients are supported:spring-doc.cadn.net.cn




Reactor Nettyspring-doc.cadn.net.cn


Jetty RS clientspring-doc.cadn.net.cn


Apache HttpClientspring-doc.cadn.net.cn


JDK HttpClientspring-doc.cadn.net.cn




If multiple clients are available on the classpath, the most preferred client will be used.spring-doc.cadn.net.cn


The spring-boot-starter-webflux starter depends on io.projectreactor.netty:reactor-netty by default, which brings both server and client implementations.
If you choose to use Jetty as a reactive server instead, you should add a dependency on the Jetty Reactive HTTP client library, org.eclipse.jetty:jetty-reactive-httpclient.
Using the same technology for server and client has its advantages, as it will automatically share HTTP resources between client and server.spring-doc.cadn.net.cn


Developers can override the resource configuration for Jetty and Reactor Netty by providing a custom ReactorResourceFactory or JettyResourceFactory bean - this will be applied to both clients and servers.spring-doc.cadn.net.cn


If you wish to override that choice for the client, you can define your own ClientHttpConnector bean and have full control over the client configuration.spring-doc.cadn.net.cn


You can learn more about the WebClient configuration options in the Spring Framework reference documentation.spring-doc.cadn.net.cn



WebClient Customization

There are three main approaches to WebClient customization, depending on how broadly you want the customizations to apply.spring-doc.cadn.net.cn


To make the scope of any customizations as narrow as possible, inject the auto-configured WebClient.Builder and then call its methods as required.
WebClient.Builder instances are stateful: Any change on the builder is reflected in all clients subsequently created with it.
If you want to create several clients with the same builder, you can also consider cloning the builder with WebClient.Builder other = builder.clone();.spring-doc.cadn.net.cn


To make an application-wide, additive customization to all WebClient.Builder instances, you can declare WebClientCustomizer beans and change the WebClient.Builder locally at the point of injection.spring-doc.cadn.net.cn


Finally, you can fall back to the original API and use WebClient.create().
In that case, no auto-configuration or WebClientCustomizer is applied.spring-doc.cadn.net.cn



WebClient SSL Support

If you need custom SSL configuration on the ClientHttpConnector used by the WebClient, you can inject a WebClientSsl instance that can be used with the builder’s apply method.spring-doc.cadn.net.cn


The WebClientSsl interface provides access to any SSL bundles that you have defined in your application.properties or application.yaml file.spring-doc.cadn.net.cn


The following code shows a typical example:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import reactor.core.publisher.Mono;

import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientSsl;
import org.springframework.stereotype.Service;
import org.springframework.web.reactive.function.client.WebClient;

@Service
public class MyService {

	private final WebClient webClient;

	public MyService(WebClient.Builder webClientBuilder, WebClientSsl ssl) {
		this.webClient = webClientBuilder.baseUrl("https://example.org").apply(ssl.fromBundle("mybundle")).build();
	}

	public Mono<Details> someRestCall(String name) {
		return this.webClient.get().uri("/{name}/details", name).retrieve().bodyToMono(Details.class);
	}

}







import org.springframework.boot.autoconfigure.web.reactive.function.client.WebClientSsl
import org.springframework.stereotype.Service
import org.springframework.web.reactive.function.client.WebClient
import reactor.core.publisher.Mono

@Service
class MyService(webClientBuilder: WebClient.Builder, ssl: WebClientSsl) {

	private val webClient: WebClient

	init {
		webClient = webClientBuilder.baseUrl("https://example.org")
				.apply(ssl.fromBundle("mybundle")).build()
	}

	fun someRestCall(name: String?): Mono<Details> {
		return webClient.get().uri("/{name}/details", name)
				.retrieve().bodyToMono(Details::class.java)
	}

}



RestClient


If you are not using Spring WebFlux or Project Reactor in your application we recommend that you use RestClient to call remote REST services.spring-doc.cadn.net.cn


The RestClient interface provides a functional style blocking API.spring-doc.cadn.net.cn


Spring Boot creates and pre-configures a prototype RestClient.Builder bean for you.
It is strongly advised to inject it in your components and use it to create RestClient instances.
Spring Boot is configuring that builder with HttpMessageConverters and an appropriate ClientHttpRequestFactory.spring-doc.cadn.net.cn


The following code shows a typical example:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import org.springframework.stereotype.Service;
import org.springframework.web.client.RestClient;

@Service
public class MyService {

	private final RestClient restClient;

	public MyService(RestClient.Builder restClientBuilder) {
		this.restClient = restClientBuilder.baseUrl("https://example.org").build();
	}

	public Details someRestCall(String name) {
		return this.restClient.get().uri("/{name}/details", name).retrieve().body(Details.class);
	}

}







import org.springframework.boot.docs.io.restclient.restclient.ssl.Details
import org.springframework.stereotype.Service
import org.springframework.web.client.RestClient

@Service
class MyService(restClientBuilder: RestClient.Builder) {

	private val restClient: RestClient

	init {
		restClient = restClientBuilder.baseUrl("https://example.org").build()
	}

	fun someRestCall(name: String?): Details {
		return restClient.get().uri("/{name}/details", name)
				.retrieve().body(Details::class.java)!!
	}

}







RestClient Customization

There are three main approaches to RestClient customization, depending on how broadly you want the customizations to apply.spring-doc.cadn.net.cn


To make the scope of any customizations as narrow as possible, inject the auto-configured RestClient.Builder and then call its methods as required.
RestClient.Builder instances are stateful: Any change on the builder is reflected in all clients subsequently created with it.
If you want to create several clients with the same builder, you can also consider cloning the builder with RestClient.Builder other = builder.clone();.spring-doc.cadn.net.cn


To make an application-wide, additive customization to all RestClient.Builder instances, you can declare RestClientCustomizer beans and change the RestClient.Builder locally at the point of injection.spring-doc.cadn.net.cn


Finally, you can fall back to the original API and use RestClient.create().
In that case, no auto-configuration or RestClientCustomizer is applied.spring-doc.cadn.net.cn








You can also change the global HTTP client configuration.






RestClient SSL Support

If you need custom SSL configuration on the ClientHttpRequestFactory used by the RestClient, you can inject a RestClientSsl instance that can be used with the builder’s apply method.spring-doc.cadn.net.cn


The RestClientSsl interface provides access to any SSL bundles that you have defined in your application.properties or application.yaml file.spring-doc.cadn.net.cn


The following code shows a typical example:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import org.springframework.boot.autoconfigure.web.client.RestClientSsl;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestClient;

@Service
public class MyService {

	private final RestClient restClient;

	public MyService(RestClient.Builder restClientBuilder, RestClientSsl ssl) {
		this.restClient = restClientBuilder.baseUrl("https://example.org").apply(ssl.fromBundle("mybundle")).build();
	}

	public Details someRestCall(String name) {
		return this.restClient.get().uri("/{name}/details", name).retrieve().body(Details.class);
	}

}







import org.springframework.boot.autoconfigure.web.client.RestClientSsl
import org.springframework.boot.docs.io.restclient.restclient.ssl.settings.Details
import org.springframework.stereotype.Service
import org.springframework.web.client.RestClient

@Service
class MyService(restClientBuilder: RestClient.Builder, ssl: RestClientSsl) {

	private val restClient: RestClient

	init {
		restClient = restClientBuilder.baseUrl("https://example.org")
				.apply(ssl.fromBundle("mybundle")).build()
	}

	fun someRestCall(name: String?): Details {
		return restClient.get().uri("/{name}/details", name)
				.retrieve().body(Details::class.java)!!
	}

}







If you need to apply other customization in addition to an SSL bundle, you can use the ClientHttpRequestFactorySettings class with ClientHttpRequestFactoryBuilder:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import java.time.Duration;

import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
import org.springframework.boot.ssl.SslBundles;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestClient;

@Service
public class MyService {

	private final RestClient restClient;

	public MyService(RestClient.Builder restClientBuilder, SslBundles sslBundles) {
		ClientHttpRequestFactorySettings settings = ClientHttpRequestFactorySettings
			.ofSslBundle(sslBundles.getBundle("mybundle"))
			.withReadTimeout(Duration.ofMinutes(2));
		ClientHttpRequestFactory requestFactory = ClientHttpRequestFactoryBuilder.detect().build(settings);
		this.restClient = restClientBuilder.baseUrl("https://example.org").requestFactory(requestFactory).build();
	}

	public Details someRestCall(String name) {
		return this.restClient.get().uri("/{name}/details", name).retrieve().body(Details.class);
	}

}







import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
import org.springframework.boot.ssl.SslBundles
import org.springframework.stereotype.Service
import org.springframework.web.client.RestClient
import java.time.Duration

@Service
class MyService(restClientBuilder: RestClient.Builder, sslBundles: SslBundles) {

	private val restClient: RestClient

	init {
		val settings = ClientHttpRequestFactorySettings.defaults()
				.withReadTimeout(Duration.ofMinutes(2))
				.withSslBundle(sslBundles.getBundle("mybundle"))
		val requestFactory = ClientHttpRequestFactoryBuilder.detect().build(settings);
		restClient = restClientBuilder
				.baseUrl("https://example.org")
				.requestFactory(requestFactory).build()
	}

	fun someRestCall(name: String?): Details {
		return restClient.get().uri("/{name}/details", name).retrieve().body(Details::class.java)!!
	}

}










RestTemplate


Spring Framework’s RestTemplate class predates RestClient and is the classic way that many applications use to call remote REST services.
You might choose to use RestTemplate when you have existing code that you don’t want to migrate to RestClient, or because you’re already familiar with the RestTemplate API.spring-doc.cadn.net.cn


Since RestTemplate instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean.
It does, however, auto-configure a RestTemplateBuilder, which can be used to create RestTemplate instances when needed.
The auto-configured RestTemplateBuilder ensures that sensible HttpMessageConverters and an appropriate ClientHttpRequestFactory are applied to RestTemplate instances.spring-doc.cadn.net.cn


The following code shows a typical example:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class MyService {

	private final RestTemplate restTemplate;

	public MyService(RestTemplateBuilder restTemplateBuilder) {
		this.restTemplate = restTemplateBuilder.build();
	}

	public Details someRestCall(String name) {
		return this.restTemplate.getForObject("/{name}/details", Details.class, name);
	}

}







import org.springframework.boot.web.client.RestTemplateBuilder
import org.springframework.stereotype.Service
import org.springframework.web.client.RestTemplate

@Service
class MyService(restTemplateBuilder: RestTemplateBuilder) {

	private val restTemplate: RestTemplate

	init {
		restTemplate = restTemplateBuilder.build()
	}

	fun someRestCall(name: String): Details {
		return restTemplate.getForObject("/{name}/details", Details::class.java, name)!!
	}

}







RestTemplateBuilder includes a number of useful methods that can be used to quickly configure a RestTemplate.
For example, to add BASIC authentication support, you can use builder.basicAuthentication("user", "password").build().spring-doc.cadn.net.cn


RestTemplate Customization

There are three main approaches to RestTemplate customization, depending on how broadly you want the customizations to apply.spring-doc.cadn.net.cn


To make the scope of any customizations as narrow as possible, inject the auto-configured RestTemplateBuilder and then call its methods as required.
Each method call returns a new RestTemplateBuilder instance, so the customizations only affect this use of the builder.spring-doc.cadn.net.cn


To make an application-wide, additive customization, use a RestTemplateCustomizer bean.
All such beans are automatically registered with the auto-configured RestTemplateBuilder and are applied to any templates that are built with it.spring-doc.cadn.net.cn


The following example shows a customizer that configures the use of a proxy for all hosts except 192.168.0.5:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import org.apache.hc.client5.http.classic.HttpClient;
import org.apache.hc.client5.http.impl.classic.HttpClientBuilder;
import org.apache.hc.client5.http.impl.routing.DefaultProxyRoutePlanner;
import org.apache.hc.client5.http.routing.HttpRoutePlanner;
import org.apache.hc.core5.http.HttpException;
import org.apache.hc.core5.http.HttpHost;
import org.apache.hc.core5.http.protocol.HttpContext;

import org.springframework.boot.web.client.RestTemplateCustomizer;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

public class MyRestTemplateCustomizer implements RestTemplateCustomizer {

	@Override
	public void customize(RestTemplate restTemplate) {
		HttpRoutePlanner routePlanner = new CustomRoutePlanner(new HttpHost("proxy.example.com"));
		HttpClient httpClient = HttpClientBuilder.create().setRoutePlanner(routePlanner).build();
		restTemplate.setRequestFactory(new HttpComponentsClientHttpRequestFactory(httpClient));
	}

	static class CustomRoutePlanner extends DefaultProxyRoutePlanner {

		CustomRoutePlanner(HttpHost proxy) {
			super(proxy);
		}

		@Override
		protected HttpHost determineProxy(HttpHost target, HttpContext context) throws HttpException {
			if (target.getHostName().equals("192.168.0.5")) {
				return null;
			}
			return super.determineProxy(target, context);
		}

	}

}







import org.apache.hc.client5.http.classic.HttpClient
import org.apache.hc.client5.http.impl.classic.HttpClientBuilder
import org.apache.hc.client5.http.impl.routing.DefaultProxyRoutePlanner
import org.apache.hc.client5.http.routing.HttpRoutePlanner
import org.apache.hc.core5.http.HttpException
import org.apache.hc.core5.http.HttpHost
import org.apache.hc.core5.http.protocol.HttpContext
import org.springframework.boot.web.client.RestTemplateCustomizer
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory
import org.springframework.web.client.RestTemplate

class MyRestTemplateCustomizer : RestTemplateCustomizer {

	override fun customize(restTemplate: RestTemplate) {
		val routePlanner: HttpRoutePlanner = CustomRoutePlanner(HttpHost("proxy.example.com"))
		val httpClient: HttpClient = HttpClientBuilder.create().setRoutePlanner(routePlanner).build()
		restTemplate.requestFactory = HttpComponentsClientHttpRequestFactory(httpClient)
	}

	internal class CustomRoutePlanner(proxy: HttpHost?) : DefaultProxyRoutePlanner(proxy) {

		@Throws(HttpException::class)
		public override fun determineProxy(target: HttpHost, context: HttpContext): HttpHost? {
			if (target.hostName == "192.168.0.5") {
				return null
			}
			return  super.determineProxy(target, context)
		}

	}

}







Finally, you can define your own RestTemplateBuilder bean.
Doing so will replace the auto-configured builder.
If you want any RestTemplateCustomizer beans to be applied to your custom builder, as the auto-configuration would have done, configure it using a RestTemplateBuilderConfigurer.
The following example exposes a RestTemplateBuilder that matches what Spring Boot’s auto-configuration would have done, except that custom connect and read timeouts are also specified:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import java.time.Duration;

import org.springframework.boot.autoconfigure.web.client.RestTemplateBuilderConfigurer;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class MyRestTemplateBuilderConfiguration {

	@Bean
	public RestTemplateBuilder restTemplateBuilder(RestTemplateBuilderConfigurer configurer) {
		return configurer.configure(new RestTemplateBuilder())
			.connectTimeout(Duration.ofSeconds(5))
			.readTimeout(Duration.ofSeconds(2));
	}

}







import org.springframework.boot.autoconfigure.web.client.RestTemplateBuilderConfigurer
import org.springframework.boot.web.client.RestTemplateBuilder
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import java.time.Duration

@Configuration(proxyBeanMethods = false)
class MyRestTemplateBuilderConfiguration {

	@Bean
	fun restTemplateBuilder(configurer: RestTemplateBuilderConfigurer): RestTemplateBuilder {
		return configurer.configure(RestTemplateBuilder()).connectTimeout(Duration.ofSeconds(5))
			.readTimeout(Duration.ofSeconds(2))
	}

}







The most extreme (and rarely used) option is to create your own RestTemplateBuilder bean without using a configurer.
In addition to replacing the auto-configured builder, this also prevents any RestTemplateCustomizer beans from being used.spring-doc.cadn.net.cn








You can also change the global HTTP client configuration.






RestTemplate SSL Support

If you need custom SSL configuration on the RestTemplate, you can apply an SSL bundle to the RestTemplateBuilder as shown in this example:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import org.springframework.boot.docs.io.restclient.resttemplate.Details;
import org.springframework.boot.ssl.SslBundles;
import org.springframework.boot.web.client.RestTemplateBuilder;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class MyService {

	private final RestTemplate restTemplate;

	public MyService(RestTemplateBuilder restTemplateBuilder, SslBundles sslBundles) {
		this.restTemplate = restTemplateBuilder.sslBundle(sslBundles.getBundle("mybundle")).build();
	}

	public Details someRestCall(String name) {
		return this.restTemplate.getForObject("/{name}/details", Details.class, name);
	}

}







import org.springframework.boot.docs.io.restclient.resttemplate.Details
import org.springframework.boot.ssl.SslBundles
import org.springframework.boot.web.client.RestTemplateBuilder
import org.springframework.stereotype.Service
import org.springframework.web.client.RestTemplate

@Service
class MyService(restTemplateBuilder: RestTemplateBuilder, sslBundles: SslBundles) {

    private val restTemplate: RestTemplate

    init {
        restTemplate = restTemplateBuilder.sslBundle(sslBundles.getBundle("mybundle")).build()
    }

    fun someRestCall(name: String): Details {
        return restTemplate.getForObject("/{name}/details", Details::class.java, name)!!
    }

}










HTTP Client Detection for RestClient and RestTemplate


Spring Boot will auto-detect which HTTP client to use with RestClient and RestTemplate depending on the libraries available on the application classpath.
In order of preference, the following clients are supported:spring-doc.cadn.net.cn




Apache HttpClientspring-doc.cadn.net.cn


Jetty HttpClientspring-doc.cadn.net.cn


Reactor Netty HttpClientspring-doc.cadn.net.cn


JDK client (java.net.http.HttpClient)spring-doc.cadn.net.cn


Simple JDK client (java.net.HttpURLConnection)spring-doc.cadn.net.cn




If multiple clients are available on the classpath, and not global configuration is provided, the most preferred client will be used.spring-doc.cadn.net.cn


Global HTTP Client Configuration

If the auto-detected HTTP client does not meet your needs, you can use the spring.http.client.factory property to pick a specific factory.
For example, if you have Apache HttpClient on your classpath, but you prefer Jetty’s HttpClient you can add the following:spring-doc.cadn.net.cn






Propertiesspring-doc.cadn.net.cn


YAMLspring-doc.cadn.net.cn






spring.http.client.factory=jetty






spring:
  http:
    client:
      factory: jetty






You can also set properties to change defaults that will be applied to all clients.
For example, you may want to change timeouts and if redirects are followed:spring-doc.cadn.net.cn






Propertiesspring-doc.cadn.net.cn


YAMLspring-doc.cadn.net.cn






spring.http.client.connect-timeout=2s
spring.http.client.read-timeout=1s
spring.http.client.redirects=dont-follow






spring:
  http:
    client:
      connect-timeout: 2s
      read-timeout: 1s
      redirects: dont-follow






For more complex customizations, you can declare your own ClientHttpRequestFactoryBuilder bean which will cause auto-configuration to back off.
This can be useful when you need to customize some of the internals of the underlying HTTP library.spring-doc.cadn.net.cn


For example, the following will use a JDK client configured with a specific ProxySelector:spring-doc.cadn.net.cn






Javaspring-doc.cadn.net.cn


Kotlinspring-doc.cadn.net.cn






import java.net.ProxySelector;

import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration(proxyBeanMethods = false)
public class MyClientHttpConfiguration {

	@Bean
	ClientHttpRequestFactoryBuilder<?> clientHttpRequestFactoryBuilder(ProxySelector proxySelector) {
		return ClientHttpRequestFactoryBuilder.jdk()
			.withHttpClientCustomizer((builder) -> builder.proxy(proxySelector));
	}

}







import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder
import org.springframework.context.annotation.Bean
import org.springframework.context.annotation.Configuration
import java.net.ProxySelector
import java.net.http.HttpClient

@Configuration(proxyBeanMethods = false)
class MyClientHttpConfiguration {

	@Bean
	fun clientHttpRequestFactoryBuilder(proxySelector: ProxySelector): ClientHttpRequestFactoryBuilder<*> {
		return ClientHttpRequestFactoryBuilder.jdk()
				.withHttpClientCustomizer { builder -> builder.proxy(proxySelector) }
	}

}