Spring Cloud Gateway快速入门Demo

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1.什么是Spring Cloud Gateway？

Spring Cloud Gateway 是一个基于 Spring Framework 和 Spring Boot 构建的 API 网关服务。它提供了一种简单而有效的方式来路由请求、提供跨领域的关注点（如安全、监控/指标和弹性）以及其他功能。Spring Cloud Gateway 旨在提供一种简单而有效的方式来路由 API 请求，并提供一些常见的网关功能，如路径重写、负载均衡、限流、熔断等。

应用场景

1. 请求路由：将客户端请求路由到不同的微服务。
2. 安全性：在网关层实现身份验证和授权。
3. 负载均衡：在多个服务实例之间分配请求。
4. 限流：限制请求的速率以保护后端服务。
5. 熔断和降级：在后端服务不可用时提供默认响应。
6. 监控和日志：收集和分析请求数据。

2.环境准备

配置hosts

127.0.0.1 node1 127.0.0.1 node2

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进去目录

欢迎大家来到IT世界,在知识的湖畔探索吧!cd D:\IdeaProjects\springcloud-demo\eureka\eureka-server

执行命令

C:\Users\Dell\.jdks\jbr-17.0.9\bin\java.exe -jar target/eureka-server-1.0-SNAPSHOT.jar --spring.profiles.active=node1 C:\Users\Dell\.jdks\jbr-17.0.9\bin\java.exe -jar target/eureka-server-1.0-SNAPSHOT.jar --spring.profiles.active=node2

访问http://127.0.0.1:8761/

3.代码工程

实验目标

• 请求路由：当用户访问 /api/users 时，Spring Cloud Gateway 会将请求路由到用户服务。当访问 /api/orders 时，路由到订单服务。
• 负载均衡：如果订单服务有多个实例，Spring Cloud Gateway 可以根据负载均衡策略将请求分发到不同的实例上。

Gateway

pom.xml

欢迎大家来到IT世界,在知识的湖畔探索吧!<?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"> <parent> <artifactId>spring-cloud-gateway</artifactId> <groupId>com.et</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>gateway</artifactId> <properties> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-webflux</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-gateway</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-netflix-eureka-client</artifactId> </dependency> </dependencies> </project>

SpringCloudGatewayApplication.java

package com.et; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class SpringCloudGatewayApplication { public static void main(String[] args) { SpringApplication.run(SpringCloudGatewayApplication.class, args); } }

application.yml

server: port: 8080 spring: application: name: gateway cloud: gateway: discovery: locator: enabled: true routes: - id: user_service uri: http://localhost:8081 predicates: - Path=/api/users/ - id: order_service uri: lb://order-service predicates: - Path=/api/orders/ eureka: client: service-url: defaultZone: http://localhost:8761/eureka/

User

pom.xml

<?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"> <parent> <artifactId>spring-cloud-gateway</artifactId> <groupId>com.et</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>users</artifactId> <properties> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies> </project>

controller

package com.et; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class UserController { @GetMapping("/api/users") public String getUsers() { return "User list"; } }

UserServiceApplication.java

package com.et; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class UserServiceApplication { public static void main(String[] args) { SpringApplication.run(UserServiceApplication.class, args); } }

application.yml

server: port: 8081

Order

pom.xml

<?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"> <parent> <artifactId>spring-cloud-gateway</artifactId> <groupId>com.et</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>order</artifactId> <properties> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId> </dependency> </dependencies> </project>

controller

package com.et; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RestController; @RestController public class OrderController { @GetMapping("/api/orders") public String getOrders() { return "Order list"; } }

OrderServiceApplication

package com.et; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class OrderServiceApplication { public static void main(String[] args) { SpringApplication.run(OrderServiceApplication.class, args); } }

application.yml

server: port: 0 #random port spring: application: name: order-service eureka: client: service-url: defaultZone: http://localhost:8761/eureka/

以上只是一些关键代码，所有代码请参见下面代码仓库

代码仓库

• https://github.com/Harries/springcloud-demo(Spring Cloud Contract )

4.测试

1. 启动用户服务，提供 /api/users 端点。
2. 启动多个订单服务实例,提供 /api/orders 端点。
3. 启动 Spring Cloud Gateway。

启动这两个服务后，通过 Spring Cloud Gateway 访问 /api/users 和 /api/orders，请求将被路由到相应的服务。

• http://127.0.0.1:8080/api/orders
• http://127.0.0.1:8080/api/users

5.引用

• https://spring.io/projects/spring-cloud-gateway