淺談SpringCloud實現簡單的微服務架構

Spring Cloud是一系列框架的有序集合。它利用Spring Boot的開發便利性巧妙地簡化了分佈式系統基礎設施的開發，如服務發現註冊、配置中心、消息總線、負載均衡、斷路器、數據監控等，都可以用Spring Boot的開發風格做到一鍵啟動和部署。 Spring並沒有重複製造輪子，它只是將目前各家公司開發的比較成熟、經得起實際考驗的服務框架組合起來，通過Spring Boot風格進行再封裝屏蔽掉了複雜的配置和實現原理，最終給開發者留出了一套簡單易懂、易部署和易維護的分佈式系統開發工具包。

接下來我們就使用SpringCloud實現一套簡單的微服務架構。

以下所有代碼都已開源到github上了，地址：https://github.com/lynnlovemin/softservice

Eureka(服務註冊與發現)

首先引入相關的依賴包

<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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-eureka-server</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>

配置application.yml

 server: port: 8761eureka: instance: hostname: localhost client: registerWithEureka: false fetchRegistry: false serviceUrl: defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

創建啟動類Application

 @EnableEurekaServer@SpringBootApplicationpublic class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); }}

運行main方法，瀏覽器訪問：http://localhost:8761，我們就能在瀏覽器看到如下界面：

說明eureka啟動成功。

接下來，我們實現負債均衡、斷路器、網關、客戶端，所有的服務都應該註冊到eureka中，並且訪問eureka就能看到所有註冊的服務

client(客戶端)

pom.xml

 <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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.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>

application.yml

 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ #這裡註冊到eureka中server: port: 8763spring: application: name: service-hi

Application類

@SpringBootApplication@EnableEurekaClient@RestControllerpublic class Application { public static void main(String[] args) { SpringApplication.run(Applicatioin.class, args); } @Value("${server.port}") String port; //這裡我們提供一個接口@RequestMapping("/hi") public String home(@RequestParam String name) { return "hi "+name+",i am from port:" +port; }}

Feign(負債均衡、斷路器)

pom.xml

 <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-hystrix-dashboard</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>

application.yml

 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/server: port: 8765spring: application: name: service-feignfeign: hystrix: enabled: true

Application類

@SpringBootApplication@EnableDiscoveryClient@EnableFeignClients@EnableHystrixDashboardpublic class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); }}

然後再提供一個service，他的作用就是做負債均衡和斷路器功能

@FeignClient(value = "service-hi",fallback = SchedualServiceHiHystric.class)public interface SchedualServiceHi { @RequestMapping(value = "/hi",method = RequestMethod.GET) String sayHiFromClientOne(@RequestParam(value = "name") String name);}

 @Componentpublic class SchedualServiceHiHystric implements SchedualServiceHi { @Override public String sayHiFromClientOne(String name) { return "sorry "+name; }}

FeignClient我們指定之前創建client時指定的name:service-hi,fallback指定服務不可用時的返回數據，這樣我們啟動多個client時就可以看到http請求時會交替訪問不同的feign端口，當停掉clien時再訪問接口會返回錯誤信息。

zuul(服務網關)

在一般情況下，我們不會直接暴露客戶端給外部，而是通過服務網關來轉發，內部服務都是在局域網內通信，外部訪問不了，通過服務網關，我們還可以統一做接口的安全性校驗，統一攔截，請看代碼：

pom.xml

 <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.9.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.boot</groupId> <artifactId>spring-boot-starter-web</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-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>

application.yml

 eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/server: port: 8080spring: application: name: service-zuulzuul: routes: api-b: path: /api/** serviceId: service-feign #凡是以api開始的請求都訪問service-feign服務

Application類

@EnableZuulProxy@EnableEurekaClient@SpringBootApplicationpublic class Application { public static void main(String[] args) { SpringApplication.run(Application.class, args); }}

啟動Application，訪問：http://localhost:8080/api/hi，就能訪問到之前我們定義的接口，接下來我們做接口的攔截：

 /** * filterType：返回一個字符串代表過濾器的類型，在zuul中定義了四種不同生命週期的過濾器類型，具體如下： pre：路由之前routing：路由之時post： 路由之後error：發送錯誤調用filterOrder：過濾的順序shouldFilter：這裡可以寫邏輯判斷，是否要過濾，本文true,永遠過濾。 run：過濾器的具體邏輯。可用很複雜，包括查sql，nosql去判斷該請求到底有沒有權限訪問。 */@Componentpublic class MyFilter extends ZuulFilter{ private static Logger log = LoggerFactory.getLogger(MyFilter.class); @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; }}

這樣我們在調用接口前會先執行MyFilter類中的run方法，在這個方法裡可以做一系列安全驗證，比如token。

好了，一個簡單的微服務架構就已經搭建完成了。

以上所有代碼都已開源到github上了，地址：https://github.com/lynnlovemin/softservice

以上所述是小編給大家介紹的SpringCloud實現簡單的微服務架構，希望對大家有所幫助，如果大家有任何疑問請給我留言，小編會及時回复