【微服务架构 - 08 - Spring Cloud】07 使用路由网关统一访问接口

喜欢ヅ旅行 2022-03-21 14:12 157阅读 0赞

#### pom.xml ####

--------------------

添加 `Zuul` 的依赖

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

#### Application ####

--------------------

增加 `@EnableZuulProxy` 注解开启 `Zuul` 功能

import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.zuul.EnableZuulProxy;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableZuulProxy
    public class ZuulApplication {
        public static void main(String[] args) {
            SpringApplication.run(ZuulApplication.class, args);
        }
    }

#### bootstrap.yml ####

*  设置端口号为：8769
 *  增加 `Zuul` 配置

spring:
      application:
        name: hello-spring-cloud-zuul
    
    server:
      port: 8769
    
    zuul:
      routes:
        api-a:
          path: /api/a/**
          serviceId: hello-spring-cloud-web-admin-ribbon
        api-b:
          path: /api/b/**
          serviceId: hello-spring-cloud-web-admin-feign

路由说明：

*  以 `/api/a` 开头的请求都转发给 `hello-spring-cloud-web-admin-ribbon` 服务
 *  以 `/api/b` 开头的请求都转发给 `hello-spring-cloud-web-admin-feign` 服务

#### 配置网关路由失败时的回调 ####

--------------------

import com.fasterxml.jackson.databind.ObjectMapper;
    import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
    import org.springframework.http.HttpHeaders;
    import org.springframework.http.HttpStatus;
    import org.springframework.http.MediaType;
    import org.springframework.http.client.ClientHttpResponse;
    import org.springframework.stereotype.Component;
    
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * 路由 hello-spring-cloud-web-admin-feign 失败时的回调
     *
     * @author Yuu
     * @version 1.0.0
     * @date 2019/2/2 12:48
     */
    @Component
    public class WebAdminFeignFallbackProvider implements FallbackProvider {
    
        @Override
        public String getRoute() {
            // ServiceId，如果需要所有调用都支持回退，则 return "*" 或 return null
            return "hello-spring-cloud-web-admin-feign";
        }
    
        /**
         * 如果请求服务失败，则返回指定的信息给调用者
         * @param route
         * @param cause
         * @return
         */
        @Override
        public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
            return new ClientHttpResponse() {
                /**
                 * 网关向 api 服务请求失败了，但是消费者客户端向网关发起的请求是成功的，
                 * 不应该把 api 的 404,500 等问题抛给客户端
                 * 网关和 api 服务集群对于客户端来说是黑盒
                 * @return
                 * @throws IOException
                 */
                @Override
                public HttpStatus getStatusCode() throws IOException {
                    return HttpStatus.OK;
                }
    
                @Override
                public int getRawStatusCode() throws IOException {
                    return HttpStatus.OK.value();
                }
    
                @Override
                public String getStatusText() throws IOException {
                    return HttpStatus.OK.getReasonPhrase();
                }
    
                @Override
                public void close() {
    
                }
    
                @Override
                public InputStream getBody() throws IOException {
                    ObjectMapper objectMapper = new ObjectMapper();
                    Map<String, Object> map = new HashMap<>();
                    map.put("status", 200);
                    map.put("message", "无法连接，请检查您的网络");
                    return new ByteArrayInputStream(objectMapper.writeValueAsString(map).getBytes("UTF-8"));
                }
    
                @Override
                public HttpHeaders getHeaders() {
                    HttpHeaders headers = new HttpHeaders();
                    // 和 getBody 中的内容编码一致
                    headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
                    return headers;
                }
            };
        }
    }