第五篇：路由网管（Zuul）

1.Zuul作用

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转发到到user服务，/api/shop转发到到shop服务。zuul默认和Ribbon结合实现了负载均衡的功能。

zuul功能：

• Authentication
• Insights
• Stress Testing
• Canary Testing
• Dynamic Routing
• Service Migration
• Load Shedding
• Security
• Static Response handling
• Active/Active traffic management

2.准备工作

使用上一篇工程

3.创建Zuul工程

创建新model，pom引入依赖

<?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">
    <parent>
        <artifactId>spring-cloud</artifactId>
        <groupId>com.niuben</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>service-zuul</artifactId>
    <packaging>jar</packaging>

    <dependencies>
        <!--Eureka依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

        <!--Web依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

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

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

</project>

编写配置文件application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8769
spring:
  application:
    name: service-zuul
zuul:
  routes:
    api-a:
      path: /api-a/**
      serviceId: service-ribbon
    api-b:
      path: /api-b/**
      serviceId: service-feign

以/api-a/ 开头的请求都转发给service-ribbon服务，以/api-b/开头的请求都转发给service-feign服务

在启动类上加上@EnableZuulProxy注解，开启zuul功能

@SpringBootApplication
@EnableZuulProxy
@EnableEurekaClient
@EnableDiscoveryClient
public class ServiceZuulApplication {

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

}

依次运行eureka-server，eureka-client，service-ribbon，service-feign，service-zuul

访问：http://localhost:8769/api-a/hi?name=fhaha浏览器显示

hi haha ,现在的端口是:8762

访问http://localhost:8769/api-b/hi?name=haha浏览器显示

hi haha ,现在的端口是:8762

4.服务过滤

zuul还能过滤，做一些安全验证

创建config层MyFilter类

@Component
@Slf4j
public class MyFilter extends ZuulFilter {

    @Override
    public String filterType() {
        return "pre";
    }

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

    @Override
    public boolean shouldFilter() {
        return true;
    }

    @Override
    public Object run() {
        RequestContext ctx = RequestContext.getCurrentContext();
        HttpServletRequest request = ctx.getRequest();
        log.info(String.format("%s >>> %s", request.getMethod(), request.getRequestURL().toString()));
        Object accessToken = request.getParameter("token");
        if (accessToken == null) {
            log.warn("token is empty");
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(401);
            try {
                ctx.getResponse().getWriter().write("token is empty");
            } catch (Exception e) {
            }

            return null;
        }
        log.info("ok");
        return null;
    }

}

filterType：返回一个字符串代表过滤器的类型，在zuul中定义了四种不同生命周期的过滤器类型

• pre：路由之前
• routing：路由之时
• post： 路由之后
• error：发送错误调用

ilterOrder：过滤的顺序

shouldFilter：这里可以写逻辑判断，是否要过滤，本文true,永远过滤

run：过滤器的具体逻辑。可用很复杂，包括查sql，nosql去判断该请求到底有没有权限访问

访问：http://localhost:8769/api-a/hi?name=fhaha浏览器显示

token is empty

访问：http://localhost:8769/api-a/hi?name=forezp&token=22

hi haha ,现在的端口是:8762

源码：https://gitee.com/niugit/spring-cloud