实例演示1：在微服务体系中引入GateWay组件

• 创建一个ServiceForGateway的SpringBoot项目，通过在控制类编写方法对外提供服务

@RestController
public class Controller {@RequestMapping("/getAccount/{id}")public String getAccount(@PathVariable String id){return "Account Info, id is:"+id;}
}

• 创建GatewayDemo项目，添加依赖到pom文件

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

ps:本次实验演练仅用到Gateway组件，所以在pom文件里面，就不需要通过dependencyManagement引入spring-cloud-alibaba-dependencies，在引入了gateway的依赖后也不需要再引入spring-boot-starter-web了。

• 配置application.yml文件相关参数，实现简单路由转发

server:port: 8080
spring:cloud:gateway:routes:# 路由id，可随便命名，但要确保唯一- id: account_route# 匹配后的地址uri: http://localhost:8090/getAccount/{id}#断言predicates:# 包含/getAccount即需转发- Path=/getAccount/{id}

• 修改application.yml文件，实现网关过滤

server:port: 8080
spring:cloud:gateway:routes:- id: StripPrefix_route# 匹配后的地址uri: http://localhost:8090predicates:- Path=/needRemoved/**filters:- StripPrefix=1- id: PrefixPath_route# 匹配后的地址uri: http://localhost:8090predicates:- Method=GETfilters:- PrefixPath=/getAccount

• 自定义全局过滤器，设置过滤器动作：

//自定义的全局性过滤器
public class MyGlobalFilter implements GlobalFilter, Ordered {//处理请求@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {String urlPath = exchange.getRequest().getURI().getPath();System.out.println(urlPath);if(urlPath.indexOf("hacker") == -1){return chain.filter(exchange);}else{ServerHttpResponse res = exchange.getResponse();String msg = "fail for hacker";byte[] bits = msg.getBytes();DataBuffer buf = res.bufferFactory().wrap(bits);res.setStatusCode(HttpStatus.BAD_REQUEST);res.getHeaders().add("Content-Type", "text/plain");return res.writeWith(Mono.just(buf));}}@Overridepublic int getOrder() {//Order值越小，优先级越高return 0;}
}

• 编写代码配置过滤器：

@Configuration
public class ConfigMyGlobalFilter {@Beanpublic GlobalFilter configFilter() {return new MyGlobalFilter();}
}

实例演示2：GateWay整合Nacos，实现负载均衡

• 创建 GateWithNacos项目，添加pom依赖，引入nacos和GateWay依赖包

<dependencies><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-gateway</artifactId></dependency><dependency><groupId>com.alibaba.cloud</groupId><artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId></dependency>
</dependencies>

• 编写启动类，添加注解，说明项目与nacos组件交互

@EnableDiscoveryClient
@SpringBootApplication
public class SpringBootApp {public static void main(String[] args) {SpringApplication.run(SpringBootApp.class, args);}}

• 配置application.yml文件，实现GateWay整合Nacos效果

server:port: 8080
spring:cloud:nacos:discovery:server-addr: 127.0.0.1:8848gateway:routes:- id: loadbalance_routeuri: lb://ServiceProvider/predicates:- Path=/callServiceByRibbon

实例演示3：通过GateWay实现灰度发布

• 创建GrayRelease项目，添加pom依赖，启动类同上一致

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

• 配置application.yml文件，实现灰度发布效果

server:port: 8080
spring:cloud:gateway:routes:- id: oldVersion_Routeuri: http://localhost:3333/getAccount/{id}predicates:- Path=/getAccount/{id}- Weight=accountGroup, 9- id: newVersion_Routeuri: http://localhost:5555/getAccount/{id}predicates:- Path=/getAccount/{id}- Weight=accountGroup, 1