Spring Cloud学习笔记8-spring cloud gateway(第二代网关)

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最新推荐文章于 2025-07-02 20:03:25 发布 · 6.2k 阅读

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title: “Spring Cloud学习笔记8-spring cloud gateway(第二代网关)”

url: “https://wsk1103.github.io/”

tags:

Spring Cloud
学习笔记

备注：

官网：http://spring.io/projects/spring-cloud

总纲：https://cloud.spring.io/spring-cloud-static/Finchley.SR2/single/spring-cloud.html

JAVA： 1.8 +

MAVEN： 3.5.0 +

Spring Boot：2.0.7.RELEASE

Spring Cloud：Finchley

说明：
This project provides an API Gateway built on top of the Spring Ecosystem, including: Spring 5, Spring Boot 2 and Project Reactor. Spring Cloud Gateway aims to provide a simple, yet effective way to route to APIs and provide cross cutting concerns to them such as: security, monitoring/metrics, and resiliency.

Spring Cloud Gateway是Spring官方基于Spring 5.0，Spring Boot 2.0和Project Reactor等技术开发的网关，Spring云网关旨在提供一种简单而有效的路由API的方法。Spring Cloud Gateway作为Spring Cloud生态系中的网关，目标是替代Netflix zuul，其不仅提供统一的路由方式，并且基于Filter链的方式提供了网关基本的功能，例如：安全，监控/埋点，和限流等。

Glossary 名词解析

Route（路由）: Route the basic building block of the gateway. It is defined by an ID, a destination URI, a collection of predicates and a collection of filters. A route is matched if aggregate predicate is true. （这是网关的基本构建块。它由一个 ID，一个目标 URI，一组断言和一组过滤器定义。如果断言为真，则路由匹配。）
Predicate（断言）: This is a Java 8 Function Predicate. The input type is a Spring Framework ServerWebExchange. This allows developers to match on anything from the HTTP request, such as headers or parameters.（这是一个 Java 8 的 Predicate。输入类型是一个 ServerWebExchange。我们可以使用它来匹配来自 HTTP 请求的任何内容，例如 headers 或参数。）
Filter（过滤器）: These are instances Spring Framework GatewayFilter constructed in with a specific factory. Here, requests and responses can be modified before or after sending the downstream request.（这是org.springframework.cloud.gateway.filter.GatewayFilter的实例，我们可以使用它修改请求和响应。）

how it work

Clients make requests to Spring Cloud Gateway. If the Gateway Handler Mapping determines that a request matches a Route, it is sent to the Gateway Web Handler. This handler runs sends the request through a filter chain that is specific to the request. The reason the filters are divided by the dotted line, is that filters may execute logic before the proxy request is sent or after. All “pre” filter logic is executed, then the proxy request is made. After the proxy request is made, the “post” filter logic is executed.

客户端向Spring Cloud Gateway发出请求。如果网关处理程序映射确定请求与路由匹配，则将其发送到网关Web处理程序。此处理程序运行通过特定于请求的过滤器链发送请求。过滤器被虚线划分的原因是过滤器可以在发送代理请求之前或之后执行逻辑。执行所有“pre”过滤器逻辑，然后进行代理请求。在发出代理请求之后，执行“post”过滤器逻辑。

VS Netflix Zuul

Zuul 基于 Servlet 2.5（使用 3.x），使用阻塞 API，它不支持任何长连接，如 WebSockets。而 Spring Cloud Gateway 建立在 Spring Framework 5，Project Reactor 和 Spring Boot 2 之上，使用非阻塞 API，支持 WebSockets，并且由于它与 Spring 紧密集成，所以将会是一个更好的开发体验。

要说缺点，其实 Spring Cloud Gateway 还是有的。目前它的文档还不是很完善，官方文档有许多还处于 TODO 状态，网络上关于它的文章也还比较少。如果你决定要使用它，那么你必须得有耐心通过自己阅读源码来解决可能遇到的问题。（2018.5.7）

引用：Spring Cloud（十三）：Spring Cloud Gateway（路由）

本项目地址：https://github.com/wsk1103/my-spring-cloud

创建项目 service-gateway

搭建方法同学习笔记1中新建module

1. 修改pom.xml

主要增加依赖为

        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-gateway</artifactId>
        </dependency>

具体pom

<?xml version="1.0" encoding="UTF-8"?>
<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>com.wsk</groupId>
    <artifactId>gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>service-gateway</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>my-spring-cloud</groupId>
        <artifactId>MySpringCloud</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>

    <properties>
        <java.version>1.8</java.version>
    </properties>