Spring Cloud基础之Discovery Service服务发现简单搭建

1.创建Discovery Server服务

//导入包，实际是通过Spring Initializr导入的，Eureka Server,DevTools,Actuactor
spring-boot-devtools
spring-cloud-starter-netflix-eureka-server
spring-boot-starter-actuator
//配置启动类注解EnableEurekaServer
@EnableEurekaServer
@SpringBootApplication
public class DiscoveryServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(DiscoveryServerApplication.class, args);
    }
}
//此时启动会报错，需要配置
spring.application.name=discovery-server
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
server.port=8761

2.创建Service服务

//导入包，实际是通过Spring Initializr导入的，Eureka Discovery,DevTools,Actuactor
spring-cloud-starter-netflix-eureka-client
spring-boot-starter-actuator
spring-boot-devtools
//配置启动类注解EnableDiscoveryClient
@EnableDiscoveryClient
@SpringBootApplication
@RestController
public class ServiceApplication {
    @Value("${service.instance.name}")
    private String instance;
    public static void main(String[] args) {
        SpringApplication.run(ServiceApplication.class, args);
    }
    @RequestMapping("/")
    public String message(){
        return "Hello from " + instance;
    }
}
//配置文件
spring.application.name=service
eureka.client.service-url.defaultZone=http://localhost:8761/eureka

3.分别配置两个启动服务，每个配置端口以及节点名称，第一个为instance1 8081，第二个为instance2 8082

//第一个节点配置
service.instance.name= instance 1
server.port=8081
//第二个节点配置
service.instance.name= instance 2
server.port=8082

4.启动后，两个servic日志中会显示204，表示注册成功

2020-04-11 21:51:03.000  INFO 964 --- [nfoReplicator-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_SERVICE/localhost:service:8081: registering service...
2020-04-11 21:51:03.072  INFO 964 --- [nfoReplicator-0] com.netflix.discovery.DiscoveryClient    : DiscoveryClient_SERVICE/localhost:service:8081 - registration status: 204

5.server端会显示两个节点注册成功

2020-04-11 21:51:03.070  INFO 899 --- [nio-8761-exec-5] c.n.e.registry.AbstractInstanceRegistry  : Registered instance SERVICE/localhost:service:8081 with status UP (replication=false)
2020-04-11 21:51:03.595  INFO 899 --- [nio-8761-exec-6] c.n.e.registry.AbstractInstanceRegistry  : Registered instance SERVICE/localhost:service:8081 with status UP (replication=true)
2020-04-11 21:52:11.887  INFO 899 --- [nio-8761-exec-3] c.n.e.registry.AbstractInstanceRegistry  : Registered instance SERVICE/192.168.31.76:service:8082 with status UP (replication=false)
2020-04-11 21:52:12.408  INFO 899 --- [nio-8761-exec-5] c.n.e.registry.AbstractInstanceRegistry  : Registered instance SERVICE/192.168.31.76:service:8082 with status UP (replication=true)

6.创建Client服务

//导入包，实际是通过Spring Initializr导入的，Eureka Discovery,DevTools,Actuactor
spring-cloud-starter-netflix-eureka-client
spring-boot-starter-actuator
spring-boot-devtools
//配置启动类注解EnableDiscoveryClient，以及后去eureka服务中注册的servic地址
@EnableDiscoveryClient
@SpringBootApplication
@RestController
public class ClientApplication {
    @Autowired
    private EurekaClient eurekaClient;
    @Autowired
    private RestTemplateBuilder restTemplateBuilder;
    public static void main(String[] args) {
        SpringApplication.run(ClientApplication.class, args);
    }
    @RequestMapping("/")
    public String callService(){
        RestTemplate restTemplate = restTemplateBuilder.build();
        InstanceInfo instanceInfo = eurekaClient.getNextServerFromEureka("service",false);
        String baseUrl = instanceInfo.getHomePageUrl();
        ResponseEntity<String> reponse =
                restTemplate.exchange(baseUrl,HttpMethod.GET,null,String.class);
        return reponse.getBody();
    }
}
//配置文件，其中设置不被发现所以设置为false
spring.application.name=client
eureka.client.service-url.defaultZone=http://localhost:8761/eureka
eureka.client.register-with-eureka=false
//启动服务调用http://localhost:8080/可以每次访问到不同的两个service节点