五、SpringCloud的学习之Zuul路由网关的讲解

一、什么是网关

1.我对他的理解就是接口网关主要是用来拦截请求的，类似nginx，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， 类似于nginx转发。为什么要用到网关？

二、举个小栗子

1.我现在写的东西都跟我前几篇的博客有关系，如果你想搞清楚，请先了解下我前几篇关于SpringCloud的文章。

2.图解

这张图片就会告诉我们为什么会引入网关，因为你如果不加网关，前端请求后端的服务，是可以直接调用的，但是存在着跨域的问题，这时候我们就引入了网关的，如上图所示，再通过网关路由到我们不同的服务调用。

三、贴代码

1.项目demo-service-member(会员服务代码)、demo-service-order(订单服务代码)请参照我的上一篇博客：https://blog.csdn.net/chenmingxu438521/article/details/90514885

2.网关项目demo-service-zuul

2.1.pom.xml

<?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>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.2.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.example</groupId> <artifactId>demo-service-zuul</artifactId> <version>0.0.1-SNAPSHOT</version> <name>demo-service-zuul</name> <description>Demo project for Spring Boot</description> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-zuul</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.RC1</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> <repositories> <repository> <id>spring-milestones</id> <name>Spring Milestones</name> <url>https://repo.spring.io/milestone</url> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> </project>

2.2.application.yml

eureka: client: serviceUrl: defaultZone: http://localhost:8888/eureka/ server: port: 8769 spring: application: name: demo-service-zuul zuul: routes: api-a: path: /api-member/** //通过访问它去找我们对应的service-id服务，下同 service-id: demo-service-member api-b: path: /api-order/** service-id: demo-service-order

2.3.项目demo-service-member(会员服务代码)添加一个接口

2.4.项目demo-service-order(订单服务代码)添加一个接口

2.5.demo-service-zuul项目启动类配置

@SpringBootApplication @EnableZuulProxy //开启网关功能 @EnableEurekaClient public class DemoServiceZuulApplication { public static void main(String[] args) { SpringApplication.run(DemoServiceZuulApplication.class, args); } }

四、测试

1.Eureka界面

2.这样就可以通过网关进行访问会员服务了

3.这样就可以通过网关进行访问订单服务了

五、添加个服务过滤（使用Zuul网关拦截参数）

1.过滤所有的请求

@Component public class MyFilter extends ZuulFilter { private static Logger log = LoggerFactory.getLogger(MyFilter.class); @Override public String filterType() { return "pre"; } @Override public int filterOrder() { return 0; } public boolean shouldFilter() { return true; } 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) { //放行可以访问后端的服务 return 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; } }

2.通过网关进行访问会员服务（不加token）

3.通过网关进行访问会员服务（加token）

六、结束

上面就是我对zuul的理解了，希望能帮到你们，也欢迎你们批评指正，共勉！！！