API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) · 课时

理解响应式基础

了解 Spring Cloud Gateway 为什么构建在非阻塞响应式技术栈之上,以及这对请求流经网关意味着什么。

第 4 / 4 课13 个步骤

理解响应式基础 是 CoddyKit 上的免费 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课时。 这是第 4 节课,共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 学习路径的一部分,你的进度在网页和 CoddyKit 应用中同步。 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课程共包含 4 节课。

本课时的部分内容尚未翻译,以英文显示。

A Different Kind of Server

Unlike a traditional Spring MVC app, Spring Cloud Gateway runs on Spring WebFlux and Project Reactor. It uses a non-blocking, event-loop server (Netty) instead of one thread per request.

This design lets the gateway handle thousands of concurrent connections with very few threads.

Blocking vs Non-Blocking

In a blocking model, a thread waits idle while a backend responds. In a non-blocking model, the thread is freed and notified later when data is ready.

  • Blocking: 1 thread tied up per in-flight request
  • Non-blocking: a handful of threads serve many requests

Mono and Flux

Reactor's core types describe asynchronous results:

  • Mono<T> emits 0 or 1 value
  • Flux<T> emits 0 to many values

The gateway returns a Mono<Void> when a request finishes processing.

Mono<String> name = Mono.just("gateway");
Flux<Integer> nums = Flux.just(1, 2, 3);

Nothing Happens Until Subscribe

Reactive streams are lazy. A Mono or Flux does nothing until something subscribes. In the gateway, the framework subscribes for you when a request arrives.

Mono<String> greeting = Mono.fromSupplier(() -> "hello");
// runs only when subscribed:
greeting.subscribe(System.out::println);

The Reactive Web Stack

The starter spring-cloud-starter-gateway pulls in WebFlux automatically. You must not add spring-boot-starter-web (the servlet/MVC stack) or startup will fail with a conflict.

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

The ServerWebExchange

Every request is wrapped in a ServerWebExchange, which holds the request and response. Filters read and mutate this exchange as the request flows through.

// inside a filter
ServerHttpRequest request = exchange.getRequest();
String path = request.getURI().getPath();

The Filter Chain

A request passes through an ordered chain. Each filter can act, then call chain.filter(exchange) to continue, and run more logic after the downstream response returns.

return chain.filter(exchange)
    .then(Mono.fromRunnable(() ->
        System.out.println("response sent")));

Why Reactive Fits a Gateway

A gateway spends most of its time waiting on the network for upstream services. Non-blocking I/O is ideal here: threads are not wasted waiting, so the gateway stays responsive under heavy load.

Avoid Blocking Calls

Calling a blocking JDBC driver or Thread.sleep inside a filter stalls the event loop and hurts every request. If you must block, offload to a bounded scheduler.

Mono.fromCallable(() -> blockingLookup())
    .subscribeOn(Schedulers.boundedElastic());

Operators Transform Streams

Operators like map, flatMap, and filter reshape the data flowing through a stream without blocking.

Flux.just(1, 2, 3, 4)
    .filter(n -> n % 2 == 0)
    .map(n -> n * 10)
    .subscribe(System.out::println); // 20, 40

Mental Model

Think of the gateway as a pipeline of asynchronous steps. A request enters, flows through predicates and filters, is forwarded reactively, and the response streams back through the same chain in reverse.

Quick Check

What underlying web stack does Spring Cloud Gateway run on?

Recap

You now understand the reactive foundation of the gateway:

  • Non-blocking I/O on Netty handles high concurrency
  • Mono and Flux model async results and are lazy
  • Each request is a ServerWebExchange flowing through a filter chain
  • Never block the event loop

This mindset underpins routes, predicates, and filters you build next.

免费开始

用 AI 导师学习 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) — 免费

在浏览器中编写并运行真实代码,获得全天候 AI 导师的即时帮助,并在网页或应用中继续学习。

课程
12
课程
48

常见问题解答

「理解响应式基础」课时是免费的吗?

是的 — 「理解响应式基础」的完整文本可在网页上免费阅读。要进行交互式练习(内置代码编辑器和全天候 AI 导师)并解锁 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课程的其余内容,请升级到 CoddyKit PRO。 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课程共包含 4 节课。

「理解响应式基础」这节课中我会学到什么?

了解 Spring Cloud Gateway 为什么构建在非阻塞响应式技术栈之上,以及这对请求流经网关意味着什么。 你通过在浏览器中直接运行的动手代码来练习 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway),全天候 AI 导师会在你学习这节课的过程中回答你的问题。

学习 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 需要有经验吗?

无需任何先前经验。CoddyKit 上的 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课程适合初学者到高级学习者,你可以从这里开始或从头开始,按照自己的节奏学习。 这是第 4 节课,共 4 节。

「理解响应式基础」课时需要多长时间?

大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动,所以你能稳步进步,并在网页和应用中从离开的地方继续。

我能在这节 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课中编写并运行代码吗?

能。每节 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway) 课都包含内置代码编辑器,你可以在浏览器中直接编写并运行真实代码,并获得即时 AI 反馈 — 无需本地设置。

此课程中的所有课时

  1. 网关与传统微服务
  2. 搭建基础网关项目
  3. 定义路由与谓词
  4. 理解响应式基础
← 返回 API Gateway & Reverse Proxy (Nginx + Spring Cloud Gateway)