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！！！

五、SpringCloud的学习之Zuul路由网关的讲解

猜你喜欢