配置
创建 WebClient 的最简单方法是通过其中一个静态工厂方法:
WebClient.create()WebClient.create(String baseUrl)
您还可以使用 WebClient.builder() 并添加更多选项:
uriBuilderFactory:自定义的UriBuilderFactory,用作基础 URL。defaultUriVariables:在扩展 URI 模板时使用的默认值。defaultHeader:每次请求的请求头。defaultCookie:每次请求的 Cookie。defaultApiVersion:每次请求的 API 版本。defaultRequest:用于自定义每次请求的Consumer。filter:每次请求的客户端过滤器。exchangeStrategies:HTTP 消息读写器的自定义设置。clientConnector:HTTP 客户端库的配置。apiVersionInserter:用于在请求中插入 API 版本值的组件。observationRegistry:用于启用 可观测性支持 的注册表。observationConvention:一个可选的自定义约定,用于提取记录的观测数据的元数据。
例如:
- Java
- Kotlin
WebClient client = WebClient.builder()
.codecs(configurer -> ... )
.build();
val webClient = WebClient.builder()
.codecs { configurer -> ... }
.build()
一旦构建完成,WebClient 就是不可变的。但是,你可以按照以下方法克隆它并构建一个修改后的副本:
- Java
- Kotlin
WebClient client1 = WebClient.builder()
.filter(filterA).filter(filterB).build();
WebClient client2 = client1.mutate()
.filter(filterC).filter(filterD).build();
// client1 has filterA, filterB
// client2 has filterA, filterB, filterC, filterD
val client1 = WebClient.builder()
.filter(filterA).filter(filterB).build()
val client2 = client1.mutate()
.filter(filterC).filter(filterD).build()
// client1 has filterA, filterB
// client2 has filterA, filterB, filterC, filterD
MaxInMemorySize
为了防止应用程序出现内存问题,编解码器在内存中缓冲数据时存在限制。默认情况下,这些限制被设置为256KB。如果这个容量不够,你将会遇到以下错误:
org.springframework.core.io.buffer.DataBufferLimitException: Exceeded limit on max bytes to buffer
要更改默认编解码器的限制,请使用以下方法:
- Java
- Kotlin
WebClient webClient = WebClient.builder()
.codecs(configurer -> configurer.defaultCodecs().maxInMemorySize(2 * 1024 * 1024))
.build();
val webClient = WebClient.builder()
.codecs { configurer -> configurer.defaultCodecs().maxInMemorySize(2 * 1024 * 1024) }
.build()
Reactor Netty
要自定义 Reactor Netty 设置,请提供一个预配置的 HttpClient:
- Java
- Kotlin
HttpClient httpClient = HttpClient.create().secure(sslSpec -> ...);
WebClient webClient = WebClient.builder()
.clientConnector(new ReactorClientHttpConnector(httpClient))
.build();
val httpClient = HttpClient.create().secure { ... }
val webClient = WebClient.builder()
.clientConnector(ReactorClientHttpConnector(httpClient))
.build()
资源
默认情况下,HttpClient 会参与全局 Reactor Netty 资源的分配,这些资源存储在 reactor.netty.http.HttpResources 中,包括事件循环线程和连接池。这是推荐的模式,因为对于事件循环的并发处理来说,固定、共享的资源更为理想。在这种模式下,全局资源会一直保持活跃状态,直到进程退出。
如果服务器与进程是同步运行的,通常没有必要进行显式的关闭操作。然而,如果服务器可以在进程中启动或停止(例如,作为WAR部署的Spring MVC应用程序),你可以声明一个类型为ReactorResourceFactory且globalResources=true(默认值)的Spring管理bean,以确保当Spring的ApplicationContext被关闭时,Reactor Netty的全局资源也会被关闭,如下例所示:
- Java
- Kotlin
@Bean
public ReactorResourceFactory reactorResourceFactory() {
return new ReactorResourceFactory();
}
@Bean
fun reactorResourceFactory() = ReactorResourceFactory()
你也可以选择不参与全局Reactor Netty资源的共享。然而,在这种模式下,确保所有Reactor Netty客户端和服务器实例使用共享资源的责任就落到了你身上,如下例所示:
- Java
- Kotlin
@Bean
public ReactorResourceFactory resourceFactory() {
ReactorResourceFactory factory = new ReactorResourceFactory();
factory.setUseGlobalResources(false); 1
return factory;
}
@Bean
public WebClient webClient() {
FUNCTION<HttpClient, HttpClient> mapper = client -> {
// Further customizations...
};
clientHttpConnector connector =
new ReactorClientHttpConnector(resourceFactory(), mapper); 2
return WebClient.builder().clientConnector(connector).build(); 3
}
创建独立于全局资源的资源。
使用
ReactorClientHttpConnector构造函数与资源工厂一起使用。将连接器插入到
WebClient.Builder中。
@Bean
fun resourceFactory() = ReactorResourceFactory().apply {
isUseGlobalResources = false 1
}
@Bean
fun webClient(): WebClient {
val mapper: (HttpClient) -> HttpClient = {
// Further customizations...
}
val connector = ReactorClientHttpConnector(resourceFactory(), mapper) 2
return WebClient.builder().clientConnector(connector).build() 3
}
创建独立于全局资源的资源。
使用
ReactorClientHttpConnector构造函数与资源工厂一起使用。- \ [#3] 将连接器插入到
WebClient.Builder中。
超时
要配置连接超时:
- Java
- Kotlin
import io.netty.channel.ChannelOption;
HttpClient httpClient = HttpClient.create()
.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10000);
WebClient webClient = WebClient.builder()
.clientConnector(new ReactorClientHttpConnector(httpClient))
.build();
import io.netty.channel.ChannelOption
val httpClient = HttpClient.create()
.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 10000);
val webClient = WebClient.builder()
.clientConnector(ReactorClientHttpConnector(httpClient))
.build();
要配置读取或写入超时:
- Java
- Kotlin
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.handler.timeout.WriteTimeoutHandler;
HttpClient httpClient = HttpClient.create()
.doOnConnected(conn -> conn
.addHandlerLast(new ReadTimeoutHandler(10))
.addHandlerLast(new WriteTimeoutHandler(10)));
// Create WebClient...
import io.netty.handler.timeout.ReadTimeoutHandler
import io.netty.handler.timeout.WriteTimeoutHandler
val httpClient = HttpClient.create()
.doOnConnected { conn -> conn
.addHandlerLast(ReadTimeoutHandler(10))
.addHandlerLast(WriteTimeoutHandler(10))
}
// Create WebClient...
要为所有请求配置响应超时时间:
- Java
- Kotlin
HttpClient httpClient = HttpClient.create()
.responseTimeout(Duration.ofSeconds(2));
// Create WebClient...
val httpClient = HttpClient.create()
.responseTimeout(Duration.ofSeconds(2));
// Create WebClient...
要为特定请求配置响应超时时间:
- Java
- Kotlin
WebClient.create().get()
.uri("https://example.org/path")
.httpRequest(httpRequest -> {
HttpClientRequest reactorRequest = httpRequest.getNativeRequest();
reactorRequest.responseTimeout(Duration.ofSeconds(2));
})
.retrieve()
.bodyToMono(String.class);
WebClient.create().get()
.uri("https://example.org/path")
.httpRequest { httpRequest: ClientHttpRequest ->
val reactorRequest = httpRequest.getNativeRequest<HttpClientRequest>()
reactorRequest.responseTimeout(Duration.ofSeconds(2))
}
.retrieve()
.bodyToMono(String::class.java)
JDK HttpClient
以下示例展示了如何自定义JDK的HttpClient:
- Java
- Kotlin
HttpClient httpClient = HttpClient.newBuilder()
.followRedirects(Redirect.NORMAL)
.connectTimeout(Duration.ofSeconds(20))
.build();
ClientHttpConnector connector =
new JdkClientHttpConnector(httpClient, new DefaultDataBufferFactory());
WebClient webClient = WebClient.builder().clientConnector(connector).build();
val httpClient = HttpClient.newBuilder()
.followRedirects(Redirect.NORMAL)
.connectTimeout(Duration.ofSeconds(20))
.build()
val connector = JdkClientHttpConnector(httpClient, DefaultDataBufferFactory())
val webClient = WebClient.builder().clientConnector(connector).build()
Jetty
以下示例展示了如何自定义Jetty的HttpClient设置:
- Java
- Kotlin
HttpClient httpClient = new HttpClient();
httpClient.setCookieStore(...);
WebClient webClient = WebClient.builder()
.clientConnector(new JettyClientHttpConnector(httpClient))
.build();
val httpClient = HttpClient()
httpClient.cookieStore = ...
val webClient = WebClient.builder()
.clientConnector(JettyClientHttpConnector(httpClient))
.build();
默认情况下,HttpClient 会创建自己的资源(Executor、ByteBufferPool、Scheduler),这些资源会保持活跃状态,直到进程退出或调用 stop() 方法为止。
你可以在多个Jetty客户端(和服务器)实例之间共享资源,并通过声明一个由Spring管理的类型为JettyResourceFactory的bean来确保当Spring的ApplicationContext关闭时,这些资源也能被关闭,如下例所示:
- Java
- Kotlin
@Bean
public JettyResourceFactory resourceFactory() {
return new JettyResourceFactory();
}
@Bean
public WebClient webClient() {
HttpClient httpClient = new HttpClient();
// Further customizations...
_ClientHttpConnector connector =
new JettyClientHttpConnector(httpClient, resourceFactory()); 1
return WebClient.builder().clientConnector(connector).build(); 2
}
使用
JettyClientHttpConnector构造函数与资源工厂(resource factory)一起使用。将该连接器(connector)插入到
WebClient.Builder中。
@Bean
fun resourceFactory() = JettyResourceFactory()
@Bean
fun webClient(): WebClient {
val httpClient = HttpClient()
// Further customizations...
val connector = JettyClientHttpConnector(httpClient, resourceFactory()) 1
return WebClient.builder().clientConnector(connector).build() 2
}
使用
JettyClientHttpConnector构造函数与资源工厂(resource factory)一起使用。将该连接器(connector)插入到
WebClient.Builder中。
HttpComponents
以下示例展示了如何自定义 Apache HttpComponents 的 HttpClient 设置:
- Java
- Kotlin
HttpAsyncClientBuilder clientBuilder = HttpAsyncClients.custom();
clientBuilder.setDefaultRequestConfig(...);
CloseableHttpAsyncClient client = clientBuilder.build();
ClientHttpConnector connector = new HttpComponentsClientHttpConnector(client);
WebClient webClient = WebClient.builder().clientConnector(connector).build();
val client = HttpAsyncClients.custom().apply {
setDefaultRequestConfig(...)
}.build()
val connector = HttpComponentsClientHttpConnector(client)
val webClient = WebClient.builder().clientConnector(connector).build()