[Feign] Spring Cloud Feign

Spring Cloud Feign

목차

1. Feign Client 정의
2. Feign Client 예제
3. Feign Client 추가 설정(심화)

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1. Feign Client 정의

Feign은 넷플릭스에서 개발한 웹 서비스 Client Binder 도구.
어노테이션을 붙이고, interface를 선언하여 쉽고 편하게 사용할 수 있다.

2. Feign Client 예제

1. spring-cloud-starter-openfeign maven 추가

    <properties>
        <java.version>1.8</java.version>
            <spring-cloud.version>Finchley.RELEASE</spring-cloud.version>
    </properties>

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

    </dependencies>
    <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>

2. @EnableFeignClients 추가 : @FeignClient를 찾아 구현체를 생성하는 역할

@SpringBootApplication
@EnableFeignClients
public class ParsingApplication {

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

}

3. @FeignClient 인터페이스 생성

@FeignClient(value = "open-api", url = "http://openapitraffic.daejeon.go.kr/api/rest/busRouteInfo/")
public interface OpenAPIClient {

    @GetMapping("/getRouteInfoAll")
    public String getRouteInfoAll(@RequestParam String serviceKey, @RequestParam String reqPage);

}

Error Message

Caused by: java.lang.ClassNotFoundException: org.springframework.boot.context.properties.ConfigurationBeanFactoryMetadata
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_281]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:418) ~[na:1.8.0_281]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:355) ~[na:1.8.0_281]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:351) ~[na:1.8.0_281]
    ... 114 common frames omitted

에러 발생 뭔가 못찾는거 같다.

해결방법 : 구글링 해보니 spring cloud reference에 Spring boot와 Spring cloud version을 맞춰줘야 한다고 한다.

spring boot vs spring cloud version

내가 사용하는 spring boot 버전이 2.4.1이므로 맞는 버전으로 수정

 <spring-cloud.version>2020.0.0</spring-cloud.version>

spring cloud version을 바꿔주니 정상 작동한다.

Test 코드

@SpringBootTest
public class FeignClientTest {

    @Autowired
    OpenAPIClient openAPIClient;

    @Test
    void getMethodFeignClientTest() {
        String serviceKey = "ERvgM5YJuigXEYahj%2FZwKcD13pTrKUYUZOwWRuamCJfozqcMh4xyI9iMPTApsOQTzGcTeRJH7KIHmywWmYxe1g%3D%3D";

        String reqPage = "1";

        String response = openAPIClient.getRouteInfoAll(serviceKey, reqPage);

        Assertions.assertNotNull(response);
    }
}

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3. Feign Client 추가 설정(심화)

Http Header 세팅 방법

1. 우선, 헤더 로그를 확인 하기 위해 feign 로그관련 설정을 yml에 추가

• feign.client.config.default : 모든 Feign Client에 대해서 적용
  • default 대신 @FeignClient 어노테이션 name 속성값으로 지정 시 해당 Feign만 적용
• feign.client.config.client-name.loggerLevel
  • NONE : 로그 없음
  • BASIC : 요청 Method, URL, 응답상태코드, 실행시간만 출력
  • HEADERS : 요청/응답 헤더 출력
  • FULL : 요청/응답 헤더, 바디, 메타데이터 모두 출력
  ※ @FeginClient의 패키지가 로깅레벨 DEBUG로 되어있어야 로그가 출력된다.

feign:
  client:
    config:
      default:
        loggerLevel: FULL
logging:
  level:
    com.server.people.xml.parsing.client.OpenAPIClient: DEBUG

2. RequestInterceptor 인터페이스를 Override하면 공통적으로 header를 세팅할수 있다.

public class FeignConfiguration implements RequestInterceptor {

    @Override
    public void apply(RequestTemplate requestTemplate) {

        requestTemplate.header("Authorization", "123456");

        requestTemplate.header("Accept", "application/xml");
    }
}

※ 주의 : @Configuration 붙이지 않기
@Configuration을 붙이면 Spring Bean으로 등록되어 모든 FeignClient에 대해 설정이 적용된다.
FeignClient마다 설정 값들이 달라질수 있기 때문에, @Configuration 어노테이션을 붙이지 않고,
@FeignClient 속성값 configuration에 생성한 config를 추가하여 원하는 Feign Client만 설정을 적용하도록 한다.

3. @FeignClient 어노테이션 configuration 설정값에 세팅한 config 추가

@FeignClient(value = "${sample.open-api.name}", url = "${sample.open-api.url}", configuration = FeignConfiguration.class)
public interface OpenAPIClient {

    @GetMapping("/getRouteInfoAll")
    public String getRouteInfoAll(@RequestParam String serviceKey, @RequestParam String reqPage);

}

결과 Feign Log : header에 세팅한 거 확인

2021-06-18 15:26:24.690 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] ---> GET http://openapitraffic.daejeon.go.kr/api/rest/busRouteInfo/getRouteInfoAll?serviceKey=ERvgM5YJuigXEYahj/ZwKcD13pTrKUYUZOwWRuamCJfozqcMh4xyI9iMPTApsOQTzGcTeRJH7KIHmywWmYxe1g%3D%3D&reqPage=1 HTTP/1.1
2021-06-18 15:26:24.691 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] Accept: application/xml
2021-06-18 15:26:24.691 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] Authorization: 123456
2021-06-18 15:26:24.691 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] ---> END HTTP (0-byte body)
2021-06-18 15:26:24.815 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] <--- HTTP/1.1 406 Not Acceptable (120ms)
2021-06-18 15:26:24.816 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] content-length: 0
2021-06-18 15:26:24.816 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] content-type: text/xml
2021-06-18 15:26:24.816 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] date: Fri, 18 Jun 2021 06:26:05 GMT
2021-06-18 15:26:24.816 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] server: Apache-Coyote/1.1
2021-06-18 15:26:24.816 DEBUG 34577 --- [           main] c.s.p.xml.parsing.client.OpenAPIClient   : [OpenAPIClient#getRouteInfoAll] <--- END HTTP (0-byte body)

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