springcloud之eureka项目搭建

eureka是什么？

eureka是netflix开的的一套服务发现框架。在框架中的主要核心角色有，服务发现，服务注册和服务提供。

eureka服务集群搭建

1.项目结构

2. 新建父级项目，父级项目pom文件，版本统一

  4.0.0

  com.xx.job
  spring-cloud-demo
  pom
  1.0-SNAPSHOT
  
    spring-cloud-payment8081
      order-consumer80
      cloud-common
    eureka-server7001
      eureka-server7002
      spring-cloud-payment8082
  
  
    UTF-8
    2.3.3.RELEASE
    Hoxton.SR12
    5.1.47
    2.0.6
    1.2.6
    1.18.20
    1.0-SNAPSHOT
    2.2.6.RELEASE
  

  
    
      
        org.springframework.boot
        spring-boot-dependencies
        ${spring.version}
        pom
        import
      
      
        org.springframework.cloud
        spring-cloud-dependencies
        ${springCloud.version}
        pom
        import
      
      
        mysql
        mysql-connector-java
        ${mysql.version}
        pom
        import
      
      
        org.mybatis
        mybatis-spring
        ${mybatis.version}
        pom
        import
      
      
        com.alibaba
        druid
        ${druid.version}
      
      
        org.projectlombok
        lombok
        ${lombak.veraion}
        provided
      
      
        org.springframework.cloud
        spring-cloud-starter-netflix-eureka-server
        ${eureka.version}
        pom
        import
      
      
        org.springframework.cloud
        spring-cloud-starter-netflix-eureka-client
        ${eureka.version}
        pom
        import
      


    
  

2.新建eureka注册中心（eureka-server7001），注册中心pom

    
        spring-cloud-demo
        com.xx.job
        1.0-SNAPSHOT
    
    4.0.0

    eureka-server7001

    eureka-server7001

    
        UTF-8
        8
        8
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-server
        
        
            junit
            junit
            test
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
    

3.注册中心yml文件配置

server:
  port: 7001

spring:
  application:
    name: eureka-server7001

eureka:
  instance:
    hostname: localhost #eureka服务端实例名称

  client:
    # false表示不向注册中心注册自己
    register-with-eureka: true
    # false 表示自己就是注册中心，我的职责是给你的维护服务实例，并不需要去检索服务
    fetch-registry: false
    service-url:
      defaultZone: http://${eureka.instance.hostname}:7002/eureka/

4.注册中心启动类

@SpringBootApplication
@EnableEurekaServer //注册中心注解
public class EurekaServer7001 {
    public static void main(String[] args) {
        SpringApplication.run(EurekaServer7001.class,args);
    }
}

5.启动之后，访问127.0.0.1:7001出现以下页面就是注册配置好了（多个注册中心配置相同，改一下端口号就好了）。

 6.eureka注册中心配置注意点：如果我们有多个注册中心，要向其它注册中心注册自己例如：

我有三个注册中心，7001，7002，7003。7002要向7001和7003注册自己，只需要在defaultZone属性中添加相应的地址就可以了。

    service-url:
      defaultZone: http://localhost:7001/eureka,http://localhost:7003/eureka

eureka服务提供者搭建

1.新建maven项目（spring-cloud-payment8081），pom文件

    
        spring-cloud-demo
        com.xx.job
        1.0-SNAPSHOT
    
    4.0.0

    spring-cloud-payment8081

    
        UTF-8
        8
        8
    

    
        
            com.xx.job
            cloud-common
            ${project.version}
        
        
            junit
            junit
            4.11
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            mysql
            mysql-connector-java
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.0.0
        
        
            com.alibaba
            druid
        
        
            org.projectlombok
            lombok
        
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
    

2.写yml文件

server:
  port: 8081

spring:
  application:
    name: spring-cloud-payment
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://127.0.0.1:3306/spring-cloud?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8


eureka:
  instance:
    instance-id: spring-cloud-payment8001
  client:
    #表示是否将自己注册进EurekaServer，默认为true
    register-with-eureka: true
    # 是否从EurekaServer抓取已有的注册信息，默认为毛白前，单节点无所谓，集群必须设置为true,才能配合ribbon使用负载均衡
    fetch-registry: true
    service-url:
      defaultZone: http://localhost:7001/eureka,http://localhost:7002/eureka

mybatis:
  type-aliases-package: com.xx.job.entity # xml匹配包
  mapper-locations: classpath:mapper/*.xml # xml放的位置

3.编写启动类-----然后启动

@EnableEurekaClient // eureka客户端注解
@SpringBootApplication
public class SpringCloudDemo8081 {

    public static void main(String[] args) {
        SpringApplication.run(SpringCloudDemo8081.class,args);
    }
}

4.刷新7001注册中心我们可以看到多了一个应用

5.多个服务提供者，基本相同改一下端口号就可以。其中的业务代码可以自己写，跟平常的springboot一样。 

服务消费方项目搭建

1.新建项目（order-consumer80）,pom文件

    
        spring-cloud-demo
        com.xx.job
        1.0-SNAPSHOT
    
    4.0.0
    order-consumer80
    order-consumer80

    
        UTF-8
        8
        8
    

    
        
            com.xx.job
            cloud-common
            1.0-SNAPSHOT
        
        
            org.springframework.boot
            spring-boot-starter-actuator
        
        
            junit
            junit
            4.11
            test
        
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.projectlombok
            lombok
        
        
            org.springframework.cloud
            spring-cloud-starter-netflix-eureka-client
        
    

2.yml文件编写

server:
  port: 81
spring:
  application:
    name: order-consumer80
eureka:
  client:
    register-with-eureka: true
    fetch-registry: true
    service-url:
      defaultZone: http://localhost:7001/eureka,http://localhost:7002/eureka

3.启动类编写 

@EnableDiscoveryClient
@EnableEurekaClient
@SpringBootApplication
public class OrderConsumer80 {
    public static void main(String[] args) {
        SpringApplication.run(OrderConsumer80.class,args);
    }
}

4.服务消费方有一点不同，我们需要调用服务提供者的接口。  我们这里使用RestTemplate进行服务调用，所以要向spring容器中注入RestTemplate。代码：

import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;

@Configuration
public class ApplicationConfig {

    @Bean
    @LoadBalanced // 多个服务提供者可以轮询调用
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }

}

5.客户端控制层代码

import com.xx.job.common.CommonResult;
import com.xx.job.entity.Payment;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.client.RestTemplate;

import java.util.List;

@RestController
@RequestMapping("/consumer")
public class ConsumerController {

    public static final String URI = "http://SPRING-CLOUD-PAYMENT";

    @Autowired
    private RestTemplate restTemplate;
    @Autowired
    private DiscoveryClient discoveryClient;

    @GetMapping("/selectById/{id}")
    public CommonResult selectById(@PathVariable Long id){
        ResponseEntity forEntity = restTemplate.getForEntity(URI + "/payment/selectById/" + id, CommonResult.class);
        CommonResult body = forEntity.getBody();
        return body;
    }

    @GetMapping("/insert")
    public CommonResult insert( Payment payment){
        ResponseEntity forEntity = restTemplate.postForEntity(URI + "/payment/insert", payment, CommonResult.class);
        return forEntity.getBody();
    }

    @GetMapping("/discovery")
    public Object discoveryClient(){
        List services = discoveryClient.getServices();
        services.forEach(x->{
            System.out.println(x);
        });

        List instances = discoveryClient.getInstances("SPRING-CLOUD-PAYMENT");
        instances.forEach(x->{
            System.out.println(x.getHost());
            System.out.println(x.getInstanceId());
            System.out.println(x.getPort());
            System.out.println(x.getServiceId());
            System.out.println(x.getUri());
            System.out.println(x.getMetadata());
            System.out.println(x.getScheme());
            System.out.println("------------------------");
        });

        return discoveryClient;
    }
}

6.启动服务消费者。在eureka初始页面看到就加一个应用就成功了。

git地址：spring-cloud-demo: spring-cloud-demo试例