SpringCloud Micro Services

SpringCloud

SpringCloud provides developers with the tools to quickly build distributed systems, including configuration management, service discovery, circuit breakers, routing, load balancing , micro broker, event bus, global lock, decision-making campaign, distributed session and so on. It is simple operating environment, it can run on a computer developers. Otherwise spring cloud-based Springboot, so there is need to develop some understanding of Springboot, if not understand, you can see the ants SpringBoot classroom curriculum.

Service providers and consumer relations

Service Provider: service being invoked

Consumers: Service was calling

Registration and service discovery ( Eureka  )

Here, the components we need to use the Spring Cloud Netflix's Eureka, eureka is a service registration and discovery module.

 

 

 

 

What is Eureka

The official presentation here Eureka Wiki . Eureka open source Netflix is a RESTful service, mainly used for registration service discovery. Eureka consists of two components: Eureka Eureka server and the client. Eureka server as a service registration server. Eureka is a client java client, to simplify the interaction with the server load balancer as polling, to provide failover for the service and support. Netflix used in its production environment is another client that weighted based traffic load balancing, resource utilization and error status.
In my opinion, Eureka appeal from the following:

Open source : you can find out the achievement, or even modify the source code.

Reliable : After Netflix years of production test environment, should use more reliable peace of mind

Fully functional : not only provides a complete registration discovery service, as well Ribbon can be used in conjunction with other services.

Based on Java : For Java programmers to use, relatively hearts bottom.

spring cloud can use Spring Cloud, it was well integrated with Eureka, very convenient to use.

 

Producer Consumer Case

 

First, create a project springcloud_eureka_service

1 Add to depend pom file 

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

<dependencyManagement>
  <dependencies>
    <!--springCloud依赖-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-dependencies</artifactId>
      <version>Greenwich.RELEASE</version>
      <type>pom</type>
      <scope>import</scope>
    </dependency>
  </dependencies>
</dependencyManagement>

 

 

2 file written application.yml

## Application name 
the Spring: 
  the Application: 
    name: eurakaserver
 
    # statement currently eurakaserver port number 
Server: 
  Port: 8888 
# configure Eureka 
Eureka: 
  Client: 
    # behalf if they are registered with the registry to 
    the Register the -with-Eureka: false 
    # show their is a registered center 
    FETCH -registry: false 
    # configure address 
    Service - url: 
      defaultzone: HTTP: // localhost: 8888 / Eureka

 

 

3 Create Launcher class

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

 

4 operating results

 

 

 

 

Second, create a project springcloud_eureka_provider producer

Introduction to the dependence file pom

<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
<dependencyManagement>
    <dependencies>
      <!--springCloud依赖-->
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Greenwich.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

 

 

 

2 Create service interfaces

public interface IDoSomeService {
    public  String doSome();
}

 

 

3 Create a service interface implementation class

@RestController
public class IDoSomeServiceImpl implements IDoSomeService {
    @RequestMapping("/doSome")

    @Override
    public String doSome() {
        System.out.println("服务提供者");
        return "eureka";
    }
}

 

 

4 file written application.yml

  ## Application name 
  the Spring: 
    the Application: 
      name: euraka - Provider 

      # statement currently eurakaserver port number 
  Server: 
    Port: 8885 
  # configure Eureka 
  Eureka: 
    Client: 


      # Configure Address 
      Service - url: 
        defaultzone: HTTP: // localhost: 8888 / Eureka

 

 

 

5 Create a launcher class

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

 

Run 6 results

 

 

 

Third, create a consumer project springcloud_euraka_consumer

Pom file node to the introduction

<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
<dependencyManagement>
    <dependencies>
      <!--springCloud依赖-->
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>Greenwich.RELEASE</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

 

 

2 创建service接口

@FeignClient("euraka-provider")
public interface IDoSomeService {
    @RequestMapping("/doSome")
    public  String doSome();
}

 

 

3 编写application.yml文件

 

  ##应用名称
  spring:
    application:
      name: euraka-comsumer

      #声明当前 eurakaserver端口号
  server:
    port: 8881
  #配置eureka
  eureka:
    client:
      #配置地址
      service-url:
        defaultZone: http://localhost:8888/eureka

 

 

4 创建Controller层

@RestController
public class IDoSomeController {
   /* @Resource
    private RestTemplate restTemplate;*/

    @Resource
    private IDoSomeService iDoSomeService;


    @RequestMapping("/doSome")

    public String doSme(){
        System.out.println("ConsumerController");
        /*return restTemplate.getForObject("http://euraka-provider/doSome",String.class);*/
       return iDoSomeService.doSome();
    }
}

 

 

5 编写程序启动类 

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

   /* @Bean
    @LoadBalanced  //实现负载均衡
    RestTemplate restTemplate(){
        return  new RestTemplate();
    }*/

   //指定负载均衡策略随即
    @Bean
    public IRule ribbonRule(){
        return new RandomRule();
    }
}

 

 

6 运行效果