<project xmlns="http://maven.apache.org/POM/4.0.0"

         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    <modelVersion>4.0.0</modelVersion>

    <groupId>com.sam</groupId>

    <artifactId>hello-consumer</artifactId>

    <version>0.0.1-SNAPSHOT</version>

    <parent>

        <groupId>org.springframework.boot</groupId>

        <artifactId>spring-boot-starter-parent</artifactId>

        <version>1.5.1.RELEASE</version>

    </parent>

    <properties>

        <javaVersion>1.8</javaVersion>

    </properties>

    <dependencyManagement>

        <dependencies>

            <dependency>

                <groupId>org.springframework.cloud</groupId>

                <artifactId>spring-cloud-dependencies</artifactId>

                <version>Camden.SR6</version>

                <type>pom</type>

                <scope>import</scope>

            </dependency>

        </dependencies>

    </dependencyManagement>

    <dependencies>

        <!-- 引入eureka 客户端依赖 -->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-eureka</artifactId>

        </dependency>

        <!-- 引入ribbon 依赖 ，用来实现负载均衡，我们这里只是使用，先不作其他介绍-->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-ribbon</artifactId>

        </dependency>

        <dependency>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>org.springframework</groupId>

            <artifactId>spring-test</artifactId>

            <version>4.3.6.RELEASE</version>

            <scope>test</scope>

        </dependency>

        <dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-test</artifactId>

            <scope>test</scope>

        </dependency>

        <!-- 引入hystrix 依赖 ，用来实现服务容错保护-->

        <dependency>

            <groupId>org.springframework.cloud</groupId>

            <artifactId>spring-cloud-starter-hystrix</artifactId>

        </dependency>

    </dependencies>

</project>

/*@SpringBootApplication +

@EnableDiscoveryClient+

@EnableCircuitBreaker

  =  @SpringCloudApplication */

@SpringCloudApplication

public class CustomerApplication {

    //@Bean 应用在方法上，用来将方法返回值设为为bean

    @Bean

    @LoadBalanced  //@LoadBalanced实现负载均衡

    public RestTemplate restTemplate() {

        return new RestTemplate();

    }

    public static void main(String[] args) {

        SpringApplication.run(CustomerApplication.class, args);

    }

}

@Service

public class ConsumerService {

    @Autowired

    RestTemplate restTemplate;

    @HystrixCommand(fallbackMethod = "errorMsg")

    public String consumer() {

        return restTemplate.getForObject("http://hello-service/hello", String.class);

    }

       /**

        * 由 @HystrixCommand(fallbackMethod = "errorMsg")

        * 可知 在起多个服务时，如果其中一个服务宕机，则会调用 errorMsg()

        * 方法； 相比在不加@EnableCircuitBreaker断路器，的包500d的错

        */

    public String errorMsg() {

        return "error!!!";

    }

}

@RestController

public class ConsumerController {

    //这里注入的restTemplate就是在com.sam.ConsumerApp中通过@Bean配置的实例

    /*@Autowired

    RestTemplate restTemplate;*/

    @Autowired

    ConsumerService consumerService;

    @RequestMapping("/consumer")

    public String helloConsumer() {

        //调用hello-service服务，注意这里用的是服务名，而不是具体的ip+port

      //  return restTemplate.getForObject("http://hello-service/hello", String.class);

        return consumerService.consumer();

    }

}