https://github.com/seaking7/java_study/tree/master/FeignClient
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FeignClient
사전준비 openfeign 추가
ext {
/**
* Spring Boot and springCloudVersion must be compatible.
* 2.6.x, 2.7.x (Starting with 2021.0.3) = 2021.0.x
* ref : https://spring.io/projects/spring-cloud
*/
// Feign
set('springCloudVersion', '2021.0.3')
}
dependencyManagement {
imports {
mavenBom "org.springframework.cloud:spring-cloud-dependencies:${springCloudVersion}"
}
}
dependencies {
implementation 'org.springframework.cloud:spring-cloud-starter-openfeign'
}@EnableFeignClients 추가, 별도 Configuration 에서 추가도 가능(basePackageClasses 정의)
@EnableFeignClients
@SpringBootApplication
public class FeignApplication {
public static void main(String[] args) {
SpringApplication.run(FeignApplication.class, args);
}
}FeignClient interface
@FeignClient(
name = "demo-client", // application.yaml에 설정해 놓은 값을 참조
url = "${feign.url.prefix}", // application.yaml에 설정해 놓은 값을 참조 (= http://localhost:8080/target_server)
configuration = DemoFeignConfig.class)
public interface DemoFeignClient {
@GetMapping("/get") // "${feign.url.prefix}/get"으로 요청
ResponseEntity<BaseResponseInfo> callGet(@RequestHeader(CUSTOM_HEADER_NAME) String customHeader,
@RequestParam("name") String name,
@RequestParam("age") Long age);
@PostMapping("/post") // "${feign.url.prefix}/post"로 요청
ResponseEntity<BaseResponseInfo> callPost(@RequestHeader(CUSTOM_HEADER_NAME) String customHeader,
@RequestBody BaseRequestInfo baseRequestInfo);
@GetMapping("/errorDecoder")
ResponseEntity<BaseResponseInfo> callErrorDecoder();
}호출부
@Service
@RequiredArgsConstructor
public class DemoService {
private final DemoFeignClient client;
public String get() {
ResponseEntity<BaseResponseInfo> response = client.callGet("CustomHeader",
"CustomName",
1L);
System.out.println("Name : " + response.getBody().getName());
System.out.println("Age : " + response.getBody().getAge());
System.out.println("Header : " + response.getBody().getHeader());
return "get";
}
public String post() {
BaseRequestInfo requestBody = BaseRequestInfo.builder()
.name("customName")
.age(1L)
.build();
ResponseEntity<BaseResponseInfo> response = client.callPost("CustomHeader",
requestBody);
System.out.println("Name : " + response.getBody().getName());
System.out.println("Age : " + response.getBody().getAge());
System.out.println("Header : " + response.getBody().getHeader());
return "post";
}
}interceptor 설정으로 호출전 동작 추가
@RequiredArgsConstructor(staticName = "of")
public final class DemoFeignInterceptor implements RequestInterceptor {
@Override
public void apply(RequestTemplate template) { // 필요에 따라 template 필드 값을 활용하자!
// get 요청일 경우
if (template.method() == HttpMethod.GET.name()) {
System.out.println("[GET] [DemoFeignInterceptor] queries : " + template.queries());
// ex) [GET] [DemoFeignInterceptor] queries : {name=[CustomName], age=[1]}
return;
}
// post 요청일 경우
String encodedRequestBody = StringUtils.toEncodedString(template.body(), UTF_8);
System.out.println("[POST] [DemoFeignInterceptor] requestBody : " + encodedRequestBody);
// ex) [POST] [DemoFeignInterceptor] requestBody : {"name":"customName","age":1}
// Do Something
// ex) requestBody 값 수정 등등
// 새로운 requestBody 값으로 설정
template.body(encodedRequestBody);
}
}interceptor Bean 등록
@Configuration
public class DemoFeignConfig {
@Bean
public DemoFeignInterceptor feignInterceptor() {
return DemoFeignInterceptor.of();
}
}로깅처리 logAndRebufferResponse 에서 로깅 커스터마이징
@Slf4j
@RequiredArgsConstructor
public class FeignCustomLogger extends Logger {
private static final int DEFAULT_SLOW_API_TIME = 3_000;
private static final String SLOW_API_NOTICE = "Slow API";
@Override
protected void log(String configKey, String format, Object... args) {
// log를 어떤 형식으로 남길지 정해준다.
// System.out.println(String.format(methodTag(configKey) + format, args));
log.info(String.format(methodTag(configKey) + format, args));
}
@Override
protected void logRequest(String configKey, Logger.Level logLevel, Request request) {
/**
* [값]
* configKey = DemoFeignClient#callGet(String,String,Long)
* logLevel = BASIC # "feign.client.config.demo-client.loggerLevel" 참고
*
* [동작 순서]
* `logRequest` 메소드 진입 -> 외부 요청 -> `logAndRebufferResponse` 메소드 진입
*
* [참고]
* request에 대한 정보는
* `logAndRebufferResponse` 메소드 파라미터인 response에도 있다.
* 그러므로 request에 대한 정보를 [logRequest, logAndRebufferResponse] 중 어디에서 남길지 정하면 된다.
* 만약 `logAndRebufferResponse`에서 남긴다면 `logRequest`는 삭제해버리자.
*/
// System.out.println(request);
log.info(request.toString());
}
@Override
protected Response logAndRebufferResponse(String configKey, Logger.Level logLevel,
Response response, long elapsedTime) throws IOException {
/**
* [참고]
* - `logAndRebufferResponse` 메소드내에선 Request, Response에 대한 정보를 log로 남길 수 있다.
* - 매소드내 코드는 "feign.Logger#logAndRebufferResponse(java.lang.String, feign.Logger.Level, feign.Response, long)"에서 가져왔다.
*
* [사용 예]
* 예상 요청 처리 시간보다 오래 걸렸다면 "Slow API"라는 log를 출력시킬 수 있다.
* ex) [DemoFeignClient#callGet] <--- HTTP/1.1 200 (115ms)
* [DemoFeignClient#callGet] connection: keep-alive
* [DemoFeignClient#callGet] content-type: application/json
* [DemoFeignClient#callGet] date: Sun, 24 Jul 2022 01:26:05 GMT
* [DemoFeignClient#callGet] keep-alive: timeout=60
* [DemoFeignClient#callGet] transfer-encoding: chunked
* [DemoFeignClient#callGet] {"name":"customName","age":1,"header":"CustomHeader"}
* [DemoFeignClient#callGet] [Slow API] elapsedTime : 3001
* [DemoFeignClient#callGet] <--- END HTTP (53-byte body)
*/
String protocolVersion = resolveProtocolVersion(response.protocolVersion());
String reason = response.reason() != null
&& logLevel.compareTo(Level.NONE) > 0 ? " " + response.reason() : "";
int status = response.status();
log(configKey, "<--- %s %s%s (%sms)", protocolVersion, status, reason, elapsedTime);
StringBuilder headerLog = new StringBuilder();
if (logLevel.ordinal() >= Level.HEADERS.ordinal()) {
for (String field : response.headers().keySet()) {
if (shouldLogResponseHeader(field)) {
for (String value : valuesOrEmpty(response.headers(), field)) {
// log(configKey, "%s: %s", field, value);
headerLog.append(value).append("/");
}
}
}
log(configKey, "header: %s", headerLog.toString());
// log(configKey, "response: %s", response.toString());
int bodyLength = 0;
if (response.body() != null && !(status == 204 || status == 205)) {
// HTTP 204 No Content "...response MUST NOT include a message-body"
// HTTP 205 Reset Content "...response MUST NOT include an entity"
if (logLevel.ordinal() >= Level.FULL.ordinal()) {
log(configKey, ""); // CRLF
}
byte[] bodyData = Util.toByteArray(response.body().asInputStream());
bodyLength = bodyData.length;
if (logLevel.ordinal() >= Level.HEADERS.ordinal() && bodyLength > 0) {
log(configKey, "%s", decodeOrDefault(bodyData, UTF_8, "Binary data"));
}
if (elapsedTime > DEFAULT_SLOW_API_TIME) {
log(configKey, "[%s] elapsedTime : %s", SLOW_API_NOTICE, elapsedTime);
}
log(configKey, "<--- END HTTP (%s-byte body)", bodyLength);
return response.toBuilder().body(bodyData).build();
} else {
log(configKey, "<--- END HTTP (%s-byte body)", bodyLength);
}
}
return response;
}
}호출 이후 Error 처리. 별도 CustomException 으로 변환 필요
public final class DemoFeignErrorDecoder implements ErrorDecoder {
private final ErrorDecoder errorDecoder = new Default();
@Override
public Exception decode(String methodKey, Response response) {
final HttpStatus httpStatus = HttpStatus.resolve(response.status());
/**
* [참고]
* 외부 컴포넌트와 통신 시
* 정의해놓은 예외 코드 일 경우엔 적절하게 핸들링하여 처리한다.
*/
if (httpStatus == HttpStatus.NOT_FOUND) {
System.out.println("[DemoFeignErrorDecoder] Http Status = " + httpStatus);
throw new RuntimeException(String.format("[RuntimeException] Http Status is %s", httpStatus));
}
return errorDecoder.decode(methodKey, response);
}
}반응형