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浅谈SpringCloud实现简单的微服务架构

2018-01-10 14:25:01 作者：lynnlovemin

Spring Cloud是一系列框架的有序集合，本文就使用SpringCloud实现一套简单的微服务架构，具有一定的参考价值，感兴趣的小伙伴们可以参考一下

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

创建启动类Application

@EnableEurekaServer
@SpringBootApplication
public 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：

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: 8763
spring:
 application:
  name: service-hi

Application类

@SpringBootApplication
@EnableEurekaClient
@RestController
public 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: 8765
spring:
 application:
  name: service-feign
feign:
 hystrix:
  enabled: true

Application类

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
@EnableHystrixDashboard
public 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);
}

@Component
public 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: 8080
spring:
 application:
  name: service-zuul
zuul:
 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
@SpringBootApplication
public 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。
 */
@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;
  }

  @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

浅谈SpringCloud实现简单的微服务架构

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