概述
在微服务架构中，需要几个基础的服务治理组件，包括服务注册与发现、服务消费、负载均衡、熔断器、只能路由、配置管理等，由这几个基础组件相互协作，共同组件了一个简单的微服务系统。一个简单的微服务系统如下图：
Zuul 简介
Zuul 的主要功能是路由转发和过滤器。路由功能是微服务的一部分，比如 /api/user 转发到 User 服务，/api/shop 转发到 Shop 服务。Zuul 默认和 Ribbon 结合实现了负载均衡的功能。
创建路由网关
pom.xml 文件如下：
<?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"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>com.ycq</groupId> <artifactId>hello-spring-cloud-dependencies</artifactId> <version>1.0.0-SNAPSHOT</version> <relativePath>../hello-spring-cloud-dependencies/pom.xml</relativePath> </parent> <artifactId>hello-spring-cloud-zuul</artifactId> <packaging>jar</packaging> <name>hello-spring-cloud-zuul</name> <dependencies> <!-- Spring Boot Begin --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!-- Spring Boot End --> <!-- Spring Cloud Begin --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-zuul</artifactId> </dependency> <!-- Spring Cloud End --> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <mainClass>com.ycq.hello.spring.cloud.zuul.ZuulApplication</mainClass> </configuration> </plugin> </plugins> </build> </project>
主要是增加了 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
package com.ycq.hello.spring.cloud.zuul; 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); } }
application.yml
- 设置端口号为：
8769 - 增加了 Zuul 配置
spring: application: name: hello-spring-cloud-zuul server: port: 8769 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ 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的服务 - 以
/api/b开头的请求都转发给hello-spring-cloud-web-admin-feign的服务
测试访问
一次运行 EurekaApplication、ServiceAdminApplication、WebAdminRibbonApplication、WebAdminFeignApplication、ZuulApplication
打开浏览器访问：http://localhost:8769/api/a/hi?message=HelloZuul 浏览器显示
You message is HelloZuul，You port is 8763
打开浏览器访问：http://localhost:8769/api/b/hi?message=HelloZuul 浏览器显示
You message is HelloZuul，You port is 8763
至此说明 Zuul 的路由功能配置成功
配置网关路由失败时的回调
package com.ycq.hello.spring.cloud.zuul.provider; 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 * Title: WebAdminFeignFallbackProvider * Description: * * @author yaoChuanQing * @date 2020-11-22 22:51 * @version 1.0.0 */ @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"; } @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; } }; } }
