Refactor: 외부 API 통신 예외를 추가한다.

build.gradle

@@ -50,6 +50,7 @@ dependencies {
     runtimeOnly 'com.mysql:mysql-connector-j'
     annotationProcessor 'org.projectlombok:lombok'
     testImplementation 'org.springframework.boot:spring-boot-starter-test'
+    testImplementation 'com.squareup.okhttp3:mockwebserver:4.12.0'
 
     testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc'
     asciidoctorExt 'org.springframework.restdocs:spring-restdocs-asciidoctor'

src/main/java/com/seong/shoutlink/global/client/api/ApiException.java

@@ -0,0 +1,8 @@
+package com.seong.shoutlink.global.client.api;
+
+public class ApiException extends RuntimeException{
+
+    public ApiException(String message) {
+        super(message);
+    }
+}

src/main/java/com/seong/shoutlink/global/client/api/RestApiClient.java

@@ -4,20 +4,28 @@
 import com.fasterxml.jackson.core.type.TypeReference;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.seong.shoutlink.domain.common.ApiClient;
-import com.seong.shoutlink.domain.exception.ErrorCode;
-import com.seong.shoutlink.domain.exception.ShoutLinkException;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
-import org.springframework.http.ResponseEntity;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatusCode;
 import org.springframework.web.client.RestClient;
 
+@Slf4j
 public class RestApiClient implements ApiClient {
 
     private final RestClient restClient;
     private final ObjectMapper objectMapper;
 
     public RestApiClient(ObjectMapper objectMapper) {
-        restClient = RestClient.create();
+        restClient = RestClient.builder()
+            .defaultStatusHandler(HttpStatusCode::is5xxServerError, (request, response) -> {
+                log.error("[API] API 서버 에러가 발생하였습니다. [response - status={}, body={}]",
+                    response.getStatusCode(),
+                    new String(response.getBody().readAllBytes(), StandardCharsets.UTF_8));
+                throw new ApiException("API 서버 에러가 발생하였습니다.");
+            })
+            .build();
         this.objectMapper = objectMapper;
     }
 
@@ -27,17 +35,26 @@ public Map<String, Object> post(
         Map<String, List<String>> uriVariables,
         Map<String, List<String>> headers,
         String requestBody) {
-        ResponseEntity<String> entity = restClient.post()
+        String responseBody = restClient.post()
             .uri(url, uriVariables)
             .headers(httpHeaders -> httpHeaders.putAll(headers))
             .body(requestBody)
             .retrieve()
-            .toEntity(String.class);
+            .onStatus(HttpStatusCode::is4xxClientError, (request, response) -> {
+                log.error("[API] 요청 형식이 잘못되었습니다. "
+                        + "[request - url={}, uriVariables={}, headers={}, body={}] "
+                        + "[response - body={}",
+                    url, uriVariables, headers, requestBody,
+                    new String(response.getBody().readAllBytes(), StandardCharsets.UTF_8));
+                throw new ApiException("요청 형식이 잘못되었습니다.");
+            })
+            .body(String.class);
 
         try {
-            return objectMapper.readValue(entity.getBody(), new TypeReference<>() {});
+            return objectMapper.readValue(responseBody, new TypeReference<>() {});
         } catch (JsonProcessingException e) {
-            throw new ShoutLinkException("API 응답을 읽는데 실패하였습니다.", ErrorCode.ILLEGAL_ARGUMENT);
+            log.error("[API] API 응답을 읽는데 실패하였습니다. [response - body={}]", responseBody);
+            throw new ApiException("API 응답을 읽는데 실패하였습니다.");
         }
     }
 }

src/test/java/com/seong/shoutlink/global/client/api/RestApiClientTest.java

@@ -0,0 +1,115 @@
+package com.seong.shoutlink.global.client.api;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.catchException;
+
+import com.seong.shoutlink.base.BaseIntegrationTest;
+import java.io.IOException;
+import java.util.Map;
+import okhttp3.HttpUrl;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+
+class RestApiClientTest extends BaseIntegrationTest {
+
+    @Autowired
+    private RestApiClient restApiClient;
+
+    MockWebServer mockServer;
+
+    @BeforeEach
+    void setUp() throws IOException {
+        mockServer = new MockWebServer();
+        mockServer.start();
+    }
+
+    @AfterEach
+    void tearDown() throws IOException {
+        mockServer.shutdown();
+    }
+
+    @Nested
+    @DisplayName("생성하면")
+    class CreateTest {
+
+        @Test
+        @DisplayName("예외(apiException): 5xx 에러일 때")
+        void whenStatusCode_5xx() {
+            //given
+            MockResponse mockResponse = new MockResponse()
+                .setResponseCode(500);
+            mockServer.enqueue(mockResponse);
+            HttpUrl baseUrl = mockServer.url("/server-error");
+
+            //when
+            Exception exception = catchException(
+                () -> restApiClient.post(baseUrl.toString(), Map.of(), Map.of(), ""));
+
+            //then
+            assertThat(exception).isInstanceOf(ApiException.class);
+        }
+    }
+
+    @Nested
+    @DisplayName("post 호출 시")
+    class WhenPost {
+
+        @Test
+        @DisplayName("성공")
+        void post() {
+            //given
+            MockResponse mockResponse = new MockResponse()
+                .addHeader("Content-Type", "application/json")
+                .setBody("{\"content\": \"hello\"}");
+            mockServer.enqueue(mockResponse);
+            HttpUrl baseUrl = mockServer.url("/success");
+
+            //when
+            Map<String, Object> response = restApiClient.post(baseUrl.toString(), Map.of(),
+                Map.of(), "");
+
+            //then
+            assertThat(response.get("content")).isEqualTo("hello");
+        }
+
+        @Test
+        @DisplayName("예외(apiException): 4xx 에러일 때")
+        void whenStatusCode_4xx() {
+            //given
+            MockResponse mockResponse = new MockResponse()
+                .setResponseCode(400);
+            mockServer.enqueue(mockResponse);
+            HttpUrl baseUrl = mockServer.url("/client-error");
+
+            //when
+            Exception exception = catchException(
+                () -> restApiClient.post(baseUrl.toString(), Map.of(), Map.of(), ""));
+
+            //then
+            assertThat(exception).isInstanceOf(ApiException.class);
+        }
+
+        @Test
+        @DisplayName("예외(apiException): 응답 형식이 json이 아닐 때")
+        void whenResponse_isNotJson() {
+            //given
+            MockResponse mockResponse = new MockResponse()
+                .setBody("not json");
+            mockServer.enqueue(mockResponse);
+            HttpUrl baseUrl = mockServer.url("/not-json");
+
+            //when
+            Exception exception = catchException(
+                () -> restApiClient.post(baseUrl.toString(), Map.of(), Map.of(), ""));
+
+            //then
+            assertThat(exception).isInstanceOf(ApiException.class);
+        }
+    }
+}