1、SpringCloud gateway三个重要的概念：路由，断言 、过滤

2、创建cloud-gateway-gateway9527 项目编写pom.xml添加依赖

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>

        <dependency>
            <groupId>com.atguigu.springcloud</groupId>
            <artifactId>cloud-api-commons</artifactId>
            <version>${project.version}</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

编写application.yml配置文件

server:
  port: 9527

spring:
  application:
    name: cloud-gateway
  cloud:
    gateway:
      routes:
        - id: payment-routh01
          uri: http://localhost:8001
          predicates:
            - Path=/payment/get/**

        - id: payment-routh02
          uri: http://localhost:8001
          predicates:
            - Path=/payment/lb/**

eureka:
  instance:
    hostname: cloud-gateway-service
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      # defaultZone: http://localhost:7001/eureka
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

编写主启动类

@SpringBootApplication
@EnableEurekaClient
public class GateWayApplication9527 {

    public static void main(String[] args) {
        SpringApplication.run(GateWayApplication9527.class,args);
    }
}

测试cloud-provider-payment8001 服务提供者自测：http://localhost:8001/payment/get/1409365580926001153

测试网关gateway服务地址转发到服务提供者：http://localhost:9527/payment/get/1409365580926001153

2、application.yml配置动态路由

server:
  port: 9527

spring:
  application:
    name: cloud-gateway
  cloud:
    gateway:
      discovery:
        locator:
          enabled: true  #开启动态路由
      routes:
        - id: payment-routh01
          uri: lb://cloud-payment-service
          predicates:
            - Path=/payment/get/**

        - id: payment-routh02
          uri: lb://cloud-payment-service
          predicates:
            - Path=/payment/lb/**


eureka:
  instance:
    hostname: cloud-gateway-service
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      # defaultZone: http://localhost:7001/eureka
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka

3、GateWay 的 Filter 自定义过滤器

@Component
@Slf4j
public class MyLogGatewayFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
        String username = exchange.getRequest().getQueryParams().getFirst("username");
        if(username == null) {
            log.info("*******************非法的请求********************");
            exchange.getResponse().setStatusCode(HttpStatus.NOT_ACCEPTABLE);
            return exchange.getResponse().setComplete();
        }
        return chain.filter(exchange);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}

测试地址：http://localhost:9527/payment/lb?username=123