浅谈SpringCloud实现简单的微服务架构

2024-07-13 10:16:22

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Spring Cloud是一系列框架的有序集合。它利用Spring Boot的开发便利性巧妙地简化了分布式系统基础设施的开发，如服务发现注册、配置中心、消息总线、负载均衡、断路器、数据监控等，都可以用Spring Boot的开发风格做到一键启动和部署。Spring并没有重复制造轮子，它只是将目前各家公司开发的比较成熟、经得起实际考验的服务框架组合起来，通过Spring Boot风格进行再封装屏蔽掉了复杂的配置和实现原理，最终给开发者留出了一套简单易懂、易部署和易维护的分布式系统开发工具包。

接下来我们就使用SpringCloud实现一套简单的微服务架构。

以下所有代码都已开源到github上了，地址：https://github.com/lynnlovemin/softservice

Eureka(服务注册与发现)

首先引入相关的依赖包

<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/

创建启动类Application

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

运行main方法，浏览器访问：http://localhost:8761，我们就能在浏览器看到如下界面：

Spring,Cloud,微服务架构,微服务

说明eureka启动成功。

接下来，我们实现负债均衡、断路器、网关、客户端，所有的服务都应该注册到eureka中，并且访问eureka就能看到所有注册的服务

client(客户端)

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/ #这里注册到eureka中server: port: 8763spring: application:  name: service-hi

Application类

@SpringBootApplication@EnableEurekaClient@RestControllerpublic class Application {  public static void main(String[] args) {    SpringApplication.run(Applicatioin.class, args);  }  @Value("${server.port}")  String port;  //这里我们提供一个接口  @RequestMapping("/hi")  public String home(@RequestParam String name) {    return "hi "+name+",i am from port:" +port;  }}

Feign(负债均衡、断路器)

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类

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

然后再提供一个service，他的作用就是做负债均衡和断路器功能

@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我们指定之前创建client时指定的name:service-hi,fallback指定服务不可用时的返回数据，这样我们启动多个client时就可以看到http请求时会交替访问不同的feign端口，当停掉clien时再访问接口会返回错误信息。

zuul(服务网关)

在一般情况下，我们不会直接暴露客户端给外部，而是通过服务网关来转发，内部服务都是在局域网内通信，外部访问不了，通过服务网关，我们还可以统一做接口的安全性校验，统一拦截，请看代码：

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开始的请求都访问service-feign服务

Application类

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

启动Application，访问：http://localhost:8080/api/hi，就能访问到之前我们定义的接口，接下来我们做接口的拦截：

/** * 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，具体如下： pre：路由之前 routing：路由之时 post： 路由之后 error：发送错误调用 filterOrder：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。 */@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;  }}

这样我们在调用接口前会先执行MyFilter类中的run方法，在这个方法里可以做一系列安全验证，比如token。

好了，一个简单的微服务架构就已经搭建完成了。

以上所有代码都已开源到github上了，地址：https://github.com/lynnlovemin/softservice

以上所述是小编给大家介绍的SpringCloud实现简单的微服务架构，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复

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