原创

Spring Cloud Gateway快速入门Demo

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

请求路由：将客户端请求路由到不同的微服务。
安全性：在网关层实现身份验证和授权。
负载均衡：在多个服务实例之间分配请求。
限流：限制请求的速率以保护后端服务。
熔断和降级：在后端服务不可用时提供默认响应。
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

进去目录

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

<?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/