springcloud第七步：fegin客户端调用工具

什么是Feign

Feign是一个声明式的伪Http客户端，它使得写Http客户端变得更简单。使用Feign，只需要创建一个接口并注解。它具有可插拔的注解特性，可使用Feign 注解和JAX-RS注解。Feign支持可插拔的编码器和解码器。Feign默认集成了Ribbon，并和Eureka结合，默认实现了负载均衡的效果。

简而言之：

• Feign 采用的是基于接口的注解
• Feign 整合了ribbon

创建service-order-feign工程

Maven依赖

<parent>

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

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

            <version>1.5.2.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</artifactId>

            </dependency>

            <dependency>

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

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

            </dependency>

            <dependency>

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

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

            </dependency>

            <dependency>

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

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

            </dependency>

            <dependency>

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

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

                  <scope>test</scope>

            </dependency>

      </dependencies>

 

      <dependencyManagement>

            <dependencies>

                  <dependency>

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

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

                       <version>Dalston.RC1</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>

 

      <repositories>

            <repository>

                  <id>spring-milestones</id>

                  <name>Spring Milestones</name>

                  <url>https://repo.spring.io/milestone</url>

                  <snapshots>

                       <enabled>false</enabled>

                  </snapshots>

            </repository>

      </repositories>

application.yml配置

eureka:

  client:

    serviceUrl:

      defaultZone: http://localhost:8888/eureka/

server:

  port: 8765

spring:

  application:

    name: service-order-feign

编写service,调用service-member

@FeignClient("service-member")

public interface MemberFeign {

      @RequestMapping("/getUserList")

      public List<String> getOrderByUserList();

}

@FeignClient 需要调用服务名称，@RequestMapping服务请求名称

演示效果

@SpringBootApplication

@EnableEurekaClient

@EnableFeignClients

public class OrderFeignApp {

 

      public static void main(String[] args) {

            SpringApplication.run(OrderFeignApp.class, args);

      }

 

}