Spring Cloud之Zuul网关路由

前端请求先通过nginx走到zuul网关服务，zuul负责路由转发、请求过滤等网关接入层的功能，默认和ribbon整合实现了负载均衡

比如说你有20个服务，暴露出去，你的调用方，如果要跟20个服务打交道，是不是很麻烦

所以比较好的一个方式，就是开发一个通用的zuul路由转发的服务，根据请求api模式，动态将请求路由转发到对应的服务

前端，主要考虑跟一个服务打交道就可以了

1、创建zuul-server工程

2、pom.xml

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>1.5.2.RELEASE</version>
	<relativePath/> <!-- lookup parent from repository -->
</parent>

<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>
</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>

3、Application

@EnableZuulProxy
@EnableEurekaClient
@SpringBootApplication
public class ServiceZuulApplication {

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

}

4、application.yml

eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
server:
  port: 8766
spring:
  application:
    name: zuul-server
zuul:
  routes:
    say-hello:
      path: /say/hello/**
      serviceId: say-hello-service
    greeting:
      path: /greeting/**
      serviceId: greeting-service

5、修改代码

在greeting-service中的返回值加入自己的标识

6、运行，依次走两种不同的api接口，zuul会路由到不同的服务上去

7、请求过滤

@Component
public class UserLoginFilter extends ZuulFilter {

    private static Logger logger = LoggerFactory.getLogger(UserLoginFilter.class);

	// pre，routing，post，error
    @Override
    public String filterType() {
        return "pre";
    }

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

	// 根据逻辑判断是否要过滤
    @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 userId = request.getParameter("userId");

        if(userId == null) {
            log.warn("userId is empty");
            ctx.setSendZuulResponse(false);
            ctx.setResponseStatusCode(401);
            try {
                ctx.getResponse().getWriter().write("userId is empty");
            }catch (Exception e){}

            return null;
        }

        log.info("ok");

        return null;
    }

}

　　

多个服务共享相同的配置，举个例子，数据库连接，redis连接，还有别的一些东西，包括一些降级开关，等等

用config统一配置中心

1、创建工程config-server

2、pom.xml

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>1.5.2.RELEASE</version>
	<relativePath/> <!-- lookup parent from repository -->
</parent>

<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-config-server</artifactId>
	</dependency>

	<dependency>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-test</artifactId>
		<scope>test</scope>
	</dependency>

	<dependency>
		<groupId>org.springframework.cloud</groupId>
		<artifactId>spring-cloud-starter-eureka</artifactId>
	</dependency>
</dependencies>

<dependencyManagement>
	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-dependencies</artifactId>
			<version>Camden.SR6</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>

2、Application

@SpringBootApplication
@EnableConfigServer
public class ConfigServerApplication {

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

3、公开的git仓库

spring cloud config，配置文件，用的是properties的格式，基于git去做

账号：roncoo-eshop
密码：roncoo123456
仓库地址：https://github.com/roncoo-eshop/roncoo-eshop-config

git怎么用，我不讲解了，自己百度或者找资料

3、application.properties

spring.application.name=config-server
server.port=8767

spring.cloud.config.server.git.uri=https://github.com/roncoo-eshop/roncoo-eshop-config
spring.cloud.config.server.git.searchPaths=config-file
spring.cloud.config.label=master
spring.cloud.config.server.git.username=roncoo-eshop
spring.cloud.config.server.git.password=roncoo123456

（1）pom.xml

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

（2）application.yml -> bootstrap.properties

spring.application.name=config-client
spring.cloud.config.label=master
spring.cloud.config.profile=dev
spring.cloud.config.uri= http://localhost:8767/
server.port=8764
eureka.client.serviceUrl.defaultZone=http://localhost:8761/eureka/
feign.hystrix.enabled=true

（3）controller

@Value("${defaultName}")
private String defaultName;