springcloud微服务实战 学习笔记三 服务消费者

第一种方式LoadBalancerClient

• 依赖

        <parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>1.5.4.RELEASE</version>
            <relativePath/> <!-- lookup parent from repository -->
        </parent>
        <properties>
            <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
            <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
            <java.version>1.8</java.version>
        </properties>
  
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-eureka-server</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
        </dependencies>
  
        <dependencyManagement>
            <dependencies>
                <dependency>
                    <groupId>org.springframework.cloud</groupId>
                    <artifactId>spring-cloud-dependencies</artifactId>
                    <version>Dalston.SR1</version>
                    <type>pom</type>
                    <scope>import</scope>
                </dependency>
            </dependencies>
        </dependencyManagement>
  
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
  

• 配置文件

    spring.application.name=eureka-consumer
    server.port=3333
    #服务注册中心
    eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
  

• application

    @EnableDiscoveryClient
    @SpringBootApplication
    public class Application {
    
        @Bean
        public RestTemplate restTemplate() {
            return new RestTemplate();
        }
    
        public static void main(String[] args) {
            new SpringApplicationBuilder(Application.class).web(true).run(args);
        }
    }
  

• controller

    @RestController
    public class DemoController {
        Logger logger = LoggerFactory.getLogger(this.getClass());
        @Autowired
        LoadBalancerClient loadBalancerClient;
        @Autowired
        RestTemplate restTemplate;
        @GetMapping("/hello")
        public String hello(){
            ServiceInstance serviceInstance = loadBalancerClient.choose("eureka-client");
            logger.info("host:"+serviceInstance.getHost()+"---port:"+serviceInstance.getPort()+"---uri"+serviceInstance.getUri());
            String url = "http://"+serviceInstance.getHost()+":"+serviceInstance.getPort()+"/hello";
            String forObject = restTemplate.getForObject(url, String.class);
    
            return forObject;
        }
    
    }
  

第二种方式Ribbon

• 依赖
  在一种方式下添加依赖

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

配置文件修改端口号即可
修改Application.java,在RestTemplate上添加注解

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

controller修改为

    @GetMapping("/hello2")
    public String hello2(){
        return restTemplate.getForObject("http://eureka-client/hello",String.class);
    }

第三种方式Feign

• 依赖
  在第一种方式下添加依赖

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

配置文件修改端口号即可

Application.java添加注解@EnableFeignClients支持Feign客户端

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

创建一个接口
@FeignClient("eureka-client")设置使用的服务名称

    @FeignClient("eureka-client")
    public interface DemoService {
    
        @GetMapping("/hello")
        String hello();
    }

controller

    @RestController
    public class DemoController {
    
        Logger logger = LoggerFactory.getLogger(this.getClass());
        @Autowired
        DemoService demoService;
        @GetMapping("/hello")
        public String hello(){
    
            return demoService.hello();
        }
    }

三种方式可以混合使用，第二种方式因为将RestTemplate对象添加了注解，所以第一种方式就不能直接使用了，只能利用其它方式发送http请求获取数据。