SpringCloud------Feign，Geteway-编程知识

SpringCloud------Feign，Geteway

Feign

所以我们使用一门新的技术：声明式的http客户端Feign

第一步：引入依赖

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

第二步：开启自动装配功能@EnableFeignClients

@MapperScan("cn.itcast.order.mapper")
@SpringBootApplication
@EnableFeignClients
public class OrderApplication{public static void main(String[] args) {SpringApplication.run(OrderApplication.class, args);}
}

第三步：编写FeginClient接口

import cn.itcast.order.pojo.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;//设置服务名称
@FeignClient("userservice")
public interface UserClient {//设置请求方式，url,返回对象，请求参数@GetMapping("/user/{id}")User findbyID(@PathVariable("id") Long id);
}

第四步：使用接口中自定义的方法

@Service
public class OrderService {@Autowiredprivate OrderMapper orderMapper;@Autowiredprivate UserClient userClient;public Order queryOrderById(Long orderId) {// 1.查询订单Order order = orderMapper.findById(orderId);//        // 2。利用RestTemplate发起http请求，查询用户
//        String url = "http://userservice/user/"+order.getUserId();//使用rureka服务名
//        User user = restTemplate.getForObject(url, User.class);//2.改成利用feign远程调用User user = userClient.findbyID(order.getUserId());//3. 封装数据order.setUser(user);// 4.返回return order;

Fegin的自定义配置

feign:client:config:default:loggerlevel: FULL

Fegin的性能优化

修改底层客户端为Apache HttpClient方式：

第一步：引入依赖

<!--        httpclient依赖--><dependency><groupId>io.github.openfeign</groupId><artifactId>feign-httpclient</artifactId></dependency>

第二步：配置连接池

feign:httpclient:enabled: true # 支持http的开关max-connections: 200max-connections-per-route: 50

Feign的最佳实践

Gateway

搭建网关

第一步：引入依赖

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

第二步：编写网关路由配置及nacos地址

server:port: 10010
spring:application:name: gatewaycloud:nacos:server-addr: localhost:8848 # nacos地址gateway:routes:- id: user-server         #路由标识，必须唯一uri: lb://userservice   #路由的目标地址predicates:             #断言，判断请求是否符合规则- Path=/user/**- id: order-serveruri: lb://orderservicepredicates:- Path=/order/**

路由断言工厂

路由过滤器

对单个路由的过滤器：

对全部路由的过滤器

全局过滤器

自定义类，实现GlobalFilter

@Component
//@Order(-1)  //定义优先级
public class AuthorizeFilter implements GlobalFilter, Ordered {@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {//1，获取请求参数ServerHttpRequest request = exchange.getRequest();MultiValueMap<String, String> queryParams = request.getQueryParams();//2，获取参数中的authorization参数String authorization = queryParams.getFirst("authorization");//3，判断参数if("admin".equals(authorization)){//4，是放行return chain.filter(exchange);}//5，否拦截exchange.getResponse().setStatusCode(HttpStatus.UNAUTHORIZED);return  exchange.getResponse().setComplete();}//设置优先级@Overridepublic int getOrder() {return -1;}
}