springcloud(第三篇)springcloud eureka 服務(wù)注冊與發(fā)現(xiàn)

WindySky 2017-07-17

展開全文

spring cloud eureka

eureka 用以服務(wù)發(fā)現(xiàn)、服務(wù)注冊，比較流行的有consul

簡介

eureka為netflix開源軟件，分為三個部分：

eureka服務(wù):用以提供服務(wù)注冊、發(fā)現(xiàn)，已一個war的形式提供 http://search./#search%7Cga%7C1%7Ceureka-server
或者編譯源碼，將war拷貝進tomcat即可提供服務(wù)
eureka-server: 相對client端的服務(wù)端，為客戶端提供服務(wù)，通常情況下為一個
集群
eureka-client:客戶端，通過向eureka服務(wù)發(fā)現(xiàn)注冊的可用的eureka-server，向后端發(fā)送請求

spring cloud eureka

spring cloud eureka 分為兩部分

@EnableEurekaClient: 該注解表明應(yīng)用既作為eureka實例又為eureka client 可以發(fā)現(xiàn)注冊的服務(wù)
@EnableEurekaServer: 該注解表明應(yīng)用為eureka服務(wù)，有可以聯(lián)合多個服務(wù)作為集群，對外提供服務(wù)注冊以及發(fā)現(xiàn)功能

client 端

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven./POM/4.0.0"
         xmlns:xsi="http://www./2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven./POM/4.0.0 http://maven./xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.lkl.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka</artifactId>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-netflix</artifactId>
                <version>1.0.7.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        <!--表示為web工程-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--暴露各種指標-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

    </dependencies>
</project>1
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啟動應(yīng)用 Application.Java

package com.lkl.springcloud.eureka;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 * Created by liaokailin on 16/4/30.
 */
@SpringBootApplication
@EnableEurekaClient
@RestController
@EnableAutoConfiguration
public class Application {
    @RequestMapping("/")
    public String home() {
        return "Hello world";
    }

    public static void main(String[] args) {
        new SpringApplicationBuilder(Application.class).web(true).run(args);
    }
}
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創(chuàng)建配置application.properties

server.port=9090
spring.application.name=eureka.client
#eureka.client.serviceUrl.defaultZone=http://120.76.145.187:8080/eureka-server-1.4.6/v2/
eureka.client.serviceUrl.defaultZone=http://localhost:7070/eureka/
eureka.instance.appname=eureka.client.01
#eureka.client.registerWithEureka=true
#eureka.client.fetchRegistry=true
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eureka.client.serviceUrl.defaultZone 配置eureka服務(wù)地址

server

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven./POM/4.0.0"
         xmlns:xsi="http://www./2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven./POM/4.0.0 http://maven./xsd/maven-4.0.0.xsd">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.lkl.springcloud</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>

    <artifactId>eureka-server</artifactId>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-netflix</artifactId>
                <version>1.0.7.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>

        <!--表示為web工程-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--暴露各種指標-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

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


    </dependencies>

</project>1
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啟動應(yīng)用Application.java

package com.lkl.springcloud.eureka;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

/**
 * Created by liaokailin on 16/4/30.
 */
@EnableEurekaServer
@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        new SpringApplicationBuilder(Application.class).web(true).run(args);
    }

}
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配置application.yml

server:
  port: 7070
spring:
  application:
    name: server-01
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:7070/eureka/
  instance:
    metadataMap:
      instanceId: ${spring.application.name}:${spring.application.instance_id:${random.value}}1
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spring.application.name表示應(yīng)用名稱，集群名稱需要一致
defaultZone表示向自身注冊，例子中有三個server節(jié)點構(gòu)成集群，其余兩個兩個節(jié)點也向該端口注冊
instanceId 表示eureka instance 標識，需要唯一，如果不配置，多個節(jié)點最終只會有一個生效

同樣的配置第二個節(jié)點,第三個節(jié)點

啟動所有服務(wù)端應(yīng)用
訪問 http://localhost:7070 可以查看eureka注冊服務(wù)信息

訪問 http://localhost:7070/eureka/apps 可以查看metadata

服務(wù)發(fā)現(xiàn)

在客戶端創(chuàng)建Component

DiscoveryService.java

package com.lkl.springcloud.eureka;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.stereotype.Component;
import org.springframework.util.CollectionUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * Created by liaokailin on 16/4/30.
 */
@Component
@RestController
public class DiscoveryService {

    @Autowired
    private DiscoveryClient discoveryClient;

    @RequestMapping("/discovery")
    public String doDiscoveryService(){
        StringBuilder buf = new StringBuilder();
        List<String> serviceIds = discoveryClient.getServices();
        if(!CollectionUtils.isEmpty(serviceIds)){
            for(String s : serviceIds){
                System.out.println("serviceId:" + s);
                List<ServiceInstance> serviceInstances =  discoveryClient.getInstances(s);
                if(!CollectionUtils.isEmpty(serviceInstances)){
                    for(ServiceInstance si:serviceInstances){
                        buf.append("["+si.getServiceId() +" host=" +si.getHost()+" port="+si.getPort()+" uri="+si.getUri()+"]");
                    }
                }else{
                    buf.append("no service.");
                }
            }
        }


        return buf.toString();
    }

}
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