配置映射主機名和IP

為每臺虛擬主機的/etc/hosts文件加上如下內容，服務發現需要用到默認主機名作為訪問地址，這樣可以不用為每個服務實例配置IP

192.168.253.30 megumi-30 192.168.253.31 megumi-31 192.168.253.32 megumi-32

服務提供方

1.Maven依賴

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</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-zookeeper-all</artifactId></dependency></dependencies>

2. 父模塊的依賴管理

<dependencyManagement><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-dependencies</artifactId><version>1.5.3.RELEASE</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-zookeeper-dependencies</artifactId><version>1.1.1.RELEASE</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-netflix-dependencies</artifactId><version>1.3.4.RELEASE</version><type>pom</type><scope>import</scope></dependency><dependency><groupId>io.reactivex</groupId><artifactId>rxjava</artifactId><version>1.3.1</version></dependency></dependencies></dependencyManagement>

3. bootstrap.yml? (這里配置應用程序的名稱，也就是服務的名稱，用于Feign查找服務，啟用服務發現和注冊)

spring:application:name: demo-servicecloud:zookeeper:connect-string: 192.168.253.30:2181,192.168.253.31:2181,192.168.253.32:2181discovery:enabled: trueregister: true

4. App.java 用@EnableDiscoveryClient注解配置啟用服務發現

package demo;import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@EnableDiscoveryClient @SpringBootApplication public class App {public static void main(String[] args) throws Exception {SpringApplication.run(App.class, args);}}

5. DemoController.java

package demo;import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;@RestController @RequestMapping(value = "/api/demo") public class DemoController {private static final UUID INSTANCE_UUID = UUID.randomUUID();@GetMapping(value = "/instance")public Object instance() {return INSTANCE_UUID.toString();}}

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服務消費方

1. Maven依賴 (和提供方同父模塊)

<dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</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-zookeeper-all</artifactId></dependency><dependency><groupId>org.springframework.cloud</groupId><artifactId>spring-cloud-starter-feign</artifactId></dependency></dependencies>

2. bootstrap.yml? 這里選擇不注冊服務

spring:application:name: demo-appcloud:zookeeper:connect-string: 192.168.253.30:2181,192.168.253.31:2181,192.168.253.32:2181discovery:enabled: trueregister: false

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3. App.java? 同樣用注解啟用Feign客戶端和服務發現

package demo2;import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.feign.EnableFeignClients;@EnableFeignClients @EnableDiscoveryClient @SpringBootApplication public class App {public static void main(String[] args) throws Exception {SpringApplication.run(App.class, args);}}

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4. DemoService.java 用注解聲明Feign客戶端調用的服務名稱，與服務提供方yml配置的spring.application.name一致，注意這里雖然能用RequestMapping注解，但是可能引發URL路由注冊沖突的問題。

package demo2;import org.springframework.cloud.netflix.feign.FeignClient; import org.springframework.web.bind.annotation.GetMapping;@FeignClient(value = "demo-service", path = "/api/demo") //@RequestMapping(value = "/api/demo") public interface DemoService {@GetMapping(value = "/instance")String instance(); }

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5. DemoController.java

package demo2;import java.util.UUID;import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController;@RestController @RequestMapping(value = "/api/demo") public class DemoController {private static final UUID INSTANCE_UUID = UUID.randomUUID();private final DemoService remoteService;public DemoController(final DemoService remoteService) {this.remoteService = remoteService;}@GetMapping(value = "/remote-instance")public Object remoteInstance() {return this.remoteService.instance();}@GetMapping(value = "/instance")public Object instance() {return INSTANCE_UUID.toString();}}

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服務啟動后，使用zkCli運行 ls /services/demo-service ，可以看到服務的各實例已經被注冊到這里。

使用瀏覽器訪問消費方的 /api/demo/remote-instance，不停刷新可以看到值是變化的，說明客戶端負載均衡已經在正常工作了。

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轉載于:https://www.cnblogs.com/karascanvas/p/7521942.html

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