对于最新的稳定版本，请使用 Spring Framework 6.2.4！spring-doc.cadn.net.cn

过滤器

您可以注册客户端筛选器 （ExchangeFilterFunction） 通过WebClient.Builder为了拦截和修改请求，如下例所示：spring-doc.cadn.net.cn

WebClient client = WebClient.builder()
		.filter((request, next) -> {

			ClientRequest filtered = ClientRequest.from(request)
					.header("foo", "bar")
					.build();

			return next.exchange(filtered);
		})
		.build();
val client = WebClient.builder()
		.filter { request, next ->

			val filtered = ClientRequest.from(request)
					.header("foo", "bar")
					.build()

			next.exchange(filtered)
		}
		.build()

这可用于横切关注点，例如身份验证。以下示例使用 通过静态工厂方法进行基本身份验证的过滤器：spring-doc.cadn.net.cn

import static org.springframework.web.reactive.function.client.ExchangeFilterFunctions.basicAuthentication;

WebClient client = WebClient.builder()
		.filter(basicAuthentication("user", "password"))
		.build();
import org.springframework.web.reactive.function.client.ExchangeFilterFunctions.basicAuthentication

val client = WebClient.builder()
		.filter(basicAuthentication("user", "password"))
		.build()

Filters can be added or removed by mutating an existing WebClient instance, resulting in a new WebClient instance that does not affect the original one. For example:spring-doc.cadn.net.cn

import static org.springframework.web.reactive.function.client.ExchangeFilterFunctions.basicAuthentication;

WebClient client = webClient.mutate()
		.filters(filterList -> {
			filterList.add(0, basicAuthentication("user", "password"));
		})
		.build();
val client = webClient.mutate()
		.filters { it.add(0, basicAuthentication("user", "password")) }
		.build()

WebClient is a thin facade around the chain of filters followed by an ExchangeFunction. It provides a workflow to make requests, to encode to and from higher level objects, and it helps to ensure that response content is always consumed. When filters handle the response in some way, extra care must be taken to always consume its content or to otherwise propagate it downstream to the WebClient which will ensure the same. Below is a filter that handles the UNAUTHORIZED status code but ensures that any response content, whether expected or not, is released:spring-doc.cadn.net.cn

public ExchangeFilterFunction renewTokenFilter() {
	return (request, next) -> next.exchange(request).flatMap(response -> {
		if (response.statusCode().value() == HttpStatus.UNAUTHORIZED.value()) {
			return response.releaseBody()
					.then(renewToken())
					.flatMap(token -> {
						ClientRequest newRequest = ClientRequest.from(request).build();
						return next.exchange(newRequest);
					});
		} else {
			return Mono.just(response);
		}
	});
}
fun renewTokenFilter(): ExchangeFilterFunction? {
	return ExchangeFilterFunction { request: ClientRequest?, next: ExchangeFunction ->
		next.exchange(request!!).flatMap { response: ClientResponse ->
			if (response.statusCode().value() == HttpStatus.UNAUTHORIZED.value()) {
				return@flatMap response.releaseBody()
						.then(renewToken())
						.flatMap { token: String? ->
							val newRequest = ClientRequest.from(request).build()
							next.exchange(newRequest)
						}
			} else {
				return@flatMap Mono.just(response)
			}
		}
	}
}