SpringCloud-Eureka

Eureka简介

Eureka是一种基于REST(Representational State Thransfer表现层状态转移)的服务，主要用于AWS的定位服务，以便实现中间层服务器的负载均衡和故障转移。

单个注册中心整合

pom配置

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

application.yml

spring:
  application:
    name: eureka-server
server:
  port: 7000 # Server HTTP port.
eureka:
  instance:
    hostname: localhost # eureka实例的hostname
  client:
    register-with-eureka: false # 指示当前实例是否应在eureka服务器上注册其信息以供发现
    fetch-registry: false # 指示当前实例是否从eureka服务器获取注册表信息
    service-url: # 映射map。映射关于eureka服务器的url列表，map的value值可以是单个url，也可以是以,分割符分割的多个url，修改之后生效时间将在下一个循环中，由eurekaServiceUrlPollIntervalSeconds指定
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

注解@EnableEurekaServer

@EnableEurekaServer // Annotation to activate Eureka Server related configuration. 激活eureka相关配置的注解
@SpringBootApplication
public class EurekaServerApplication {

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

}

打包部署运行

mvn clean package -Dmaven.test.skip=true

java -jar xxx.jar

访问 localhost:7000

注册两个注册中心

修改application.yaml配置文件

## 新增两个配置文件

## application-peer1.yml
spring:
  application:
    name: eureka-server
server:
  port: 7001 # Server HTTP port.
eureka:
  instance:
    hostname: localhost # eureka实例的hostname
  client:
    register-with-eureka: true # 指示当前实例是否应在eureka服务器上注册其信息以供发现
    fetch-registry: true # 指示当前实例是否从eureka服务器获取注册表信息
    service-url: # 映射map。映射关于eureka服务器的url列表，map的value值可以是单个url，也可以是以,分割符分割的多个url，修改之后生效时间将在下一个循环中，由eurekaServiceUrlPollIntervalSeconds指定
      defaultZone: http://127.0.0.1:7002/eureka/
 ## application-peer2.yml
 spring:
  application:
    name: eureka-server
server:
  port: 7002 # Server HTTP port.
eureka:
  instance:
    hostname: localhost # eureka实例的hostname
  client:
    register-with-eureka: true # 指示当前实例是否应在eureka服务器上注册其信息以供发现
    fetch-registry: true # 指示当前实例是否从eureka服务器获取注册表信息
    service-url: # 映射map。映射关于eureka服务器的url列表，map的value值可以是单个url，也可以是以,分割符分割的多个url，修改之后生效时间将在下一个循环中，由eurekaServiceUrlPollIntervalSeconds指定
      defaultZone: http://127.0.0.1:7001/eureka/

打包部署

// 打包
mvn clean package -Dmaven.test.skip=true
// 运行
java -jar xxx.jar --spring.profiles.active=peer1
java -jar xxx.jpg --spring.profiles.active=peer2
// 访问
localhost:7001
localhost:7002

服务提供和调用

生成者

pom

        <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.67</version>
        </dependency>

		
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

application.yml

spring:
  application:
    name: eureka-producer
eureka:
  client:
    service-url:
      defaultZone: http://127.0.0.1:7000/eureka/
server:
  port: 8000

具体方法

@RestController
public class HelloController {
    @RequestMapping("/hello")
    public String hello(@RequestBody JSONObject requestJSON) {
        String name = requestJSON.getString("name");
        return "hello, " + name + " " + new Date();
    }
}

打包部署测试

mvn clean package -Dmaven.test.skip=true
java -jar xxx.jar
curl -H'Content-Type: application/json' -d'{"name":"huskyui"}' localhost:8000/hello
hello, huskyui Fri Mar 20 16:06:40 CST 2020

消费者

pom

 <!-- https://mvnrepository.com/artifact/com.alibaba/fastjson -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.67</version>
        </dependency>
        <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-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>

application.yml

spring:
  application:
    name: eureka-consumer
eureka:
  client:
    service-url:
      defaultZone: http://localhost:7000/eureka/
server:
  port: 9000

添加@EnableFeignClients

@EnableFeignClients
@SpringBootApplication
public class CloudEurekaConsumerApplication {

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

}

具体代码

@FeignClient(name = "eureka-producer")
public interface HelloRemote {
    @RequestMapping("/hello")
    String hello(@RequestBody JSONObject requestJSON);
}

@RestController
public class HelloController {

    @Autowired
    private HelloRemote helloRemote;

    @RequestMapping("/hello/{name}")
    public String index(@PathVariable("name")String name){
        JSONObject requestJSon = new JSONObject();
        requestJSon.put("name",name);
        return helloRemote.hello(requestJSon);
    }
}

打包部署测试

mvn clean package -Dmaven.test.skip=true
java -jar xxx.jar
curl localhost:9000/hello/huskyui
hello, huskyui Fri Mar 20 16:11:59 CST 2020

负载均衡

启动两个不同端口的生产者，启动一个消费者会实现相关效果