一、Spring Cloud Feign概念引入
通过前面的随笔,我们了解如何通过Spring Cloud ribbon进行负责均衡,如何通过Spring Cloud Hystrix进行服务断路保护,
两者作为基础工具类框架应用在各种基础设施类微服务和业务类微服务中,并且成对存在,那么有没有更高层的封装,将两者的使用
进一步简化呢? 有! 他就是Spring Cloud Feign。它基于Netflix Feign实现,整合了Spring Cloud Ribbon和Spring Cloud Hystrix,
除了提供两者强大的功能外,还提供了一种声明式的Web服务客户端定义方式。
<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>feign-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feign 依赖 --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> </dependency> </dependencies> </project>
properties文件:
server.port=9001 spring.application.name=feign-consumer eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka
启动类:
@SpringBootApplication @EnableDiscoveryClient @EnableFeignClients public class FeignConsumerApplication { public static void main(String[] args) { SpringApplication.run(FeignConsumerApplication.class, args); } }
service:
/** * 通过@FeignClient注解指定服务名来绑定服务,这里的服务名字不区分大小写 * 然后再通过@RequestMapping来绑定服务下的rest接口 * */ @FeignClient(name="hello-service") //这里的hello-service是服务提供方的名称,而 @RequestMapping的hlleo为提供方的接口,
而此接口的返回类型为String
public interface FeignConsumerService{
@RequestMapping("/hello")
public String hello();
}
controlller:
@RestController public class FeiConsumerController { @Autowired FeignConsumerService consumerService; @RequestMapping("feign-consumer") public String feignConsumer() { return consumerService.hello(); //return "feign consumer call finished!!!"; } }