1、pom.xml

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.0.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>
        <spring-cloud.version>Finchley.SR1</spring-cloud.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${spring-cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
            <!--客戶端只有當我們有了這個依賴之後，才能有那些狀態頁面的檢視，否則會報ErrorPage-->
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </dependency>
    </dependencies>
 

注意：spring-boot-starter-web依賴必須要有，如果沒有的話，會報錯

feign的依賴在Finchley版本已經需要使用openfeign，不再是之前的依賴。

2、application.yml

spring:
  application:
    name: eureka-client-consumer-feign
server:
  port: 8603
eureka:
  instance:
    prefer-ip-address: true
  client:
    service-url:
      defaultZone: http://localhost:8761/eureka/
 

3、程式碼測試

(1)服務提供者部分程式碼

    @Value("${server.port}")
    private String port;
    @RequestMapping("/getUUid/{i}")
    public String getUUid(@PathVariable("i") Integer i){
        UUID uuid = UUID.randomUUID();
        String s = i + "==="+uuid.toString();
        return s;
    }

    @RequestMapping("/getParam")
    public String getParam(@RequestBody String param){
        return param;
    }

    @RequestMapping("/getServerPort")
    public String getServerPort(){
        return port;
    }
 

（2）feign客戶端程式碼

a、啟動類程式碼

@EnableDiscoveryClient
@SpringBootApplication
@EnableFeignClients
public class EurekaClientCustomerFeignApplication {

    public static void main(String[] args) {
        SpringApplication.run(EurekaClientCustomerFeignApplication.class, args);
    }
}

b、feign介面程式碼

@FeignClient("eureka-client-provider")
public interface StoreClient {
    @RequestMapping(method = RequestMethod.POST,value = "/getUUid/{i}")
    public String getUUid(@PathVariable("i") Integer i);

    @RequestMapping("/getParam")
    public String getParam(String param);
}

注：在@FeignClient下不能使用@GetMappingz這些合成註解，@PathVariable中需要設定值不能省略

c、feign提供服務的程式碼

 @Autowired
    StoreClient storeClient;
    @RequestMapping("/getResult")
    public String getResult(){
        String uUid = storeClient.getUUid(3);
        return uUid;
    }

    @RequestMapping("getParamTest")
    public String getParamTest(){
        String ceshi = storeClient.getParam("你好");
        return ceshi;
    }

注：

     訪問返回結果是：

也就是說，我們要攜帶引數的話，位址列是可以的。如果要在方法引數中攜帶引數，那麼我們就需要使用@RequestBody的註解。

4、和ribbon一樣，feign同樣能夠覆蓋預設的配置

修改的程式碼：

@FeignClient(name="eureka-client-provider",configuration = FootConfigration.class)
public interface StoreClient {
    @RequestLine("GET /getUUid/{i}")
    public String getUUid(@PathVariable("i") Integer i);

    @RequestLine("POST /getParam")
    public String getParam(String param);
}

注：請求部分的註解必須要使用feign自己的註解，不能再使用springmvc的註解，否則就會報錯

修改配置的程式碼：

@Configuration
public class FootConfigration {
    @Bean
    public Contract feignContract() {
        return new feign.Contract.Default();
    }
}

注：這個配置類不能放在啟動類的掃描範圍之下，否則將會全域性起作用。

在中文文件中有針對於哪些配置可以進行更改進行了羅列：