[feat] 표준 응답객체 구현 및 표준 에러 정의 (#7)

* feat: 에러를 표준화할 enum 정의

* feat: 에러 응답을 표준화하기위한 예외 클래스 구현

* feat: 표준 응답객체 구현 및 GlobalExceptionHandler구현

* feat: 표준 응답 객체에 created 편의 메서드 추가

* chore: spring starter validation 의존성 추가

build.gradle

@@ -31,6 +31,9 @@ dependencies {
 	annotationProcessor 'org.projectlombok:lombok'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
 	testRuntimeOnly 'org.junit.platform:junit-platform-launcher'
+
+	// validation
+	implementation 'org.springframework.boot:spring-boot-starter-validation'
 }
 
 tasks.named('test') {

src/main/java/com/leets/team2/xclone/common/ApiData.java

@@ -0,0 +1,69 @@
+package com.leets.team2.xclone.common;
+
+import com.fasterxml.jackson.databind.annotation.JsonSerialize;
+import com.leets.team2.xclone.exception.ErrorInfo;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import lombok.Builder;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+
+@JsonSerialize
+@Builder
+@Getter
+public class ApiData<T> {
+
+  private Boolean success;
+  private T data;
+  private Integer errorCode;
+  private Object errorMessage;
+
+  public static <T> ResponseEntity<ApiData<T>> successFrom(HttpStatus httpStatus, T data) {
+    ApiData<T> apiData = ApiData.<T>builder()
+        .success(true)
+        .data(data)
+        .build();
+    return ResponseEntity.status(httpStatus).body(apiData);
+  }
+
+  public static <T> ResponseEntity<ApiData<T>> ok(T data) {
+    ApiData<T> apiData = ApiData.<T>builder()
+        .success(true)
+        .data(data)
+        .build();
+    return ResponseEntity.ok(apiData);
+  }
+
+  public static <T> ResponseEntity<ApiData<T>> created(T data) {
+    ApiData<T> apiData = ApiData.<T>builder()
+        .success(true)
+        .data(data)
+        .build();
+    return ResponseEntity.status(HttpStatus.CREATED).body(apiData);
+  }
+
+  public static <T> ResponseEntity<ApiData<T>> validationFailure(List<FieldError> fieldErrors) {
+    Map<String, String> errors = new HashMap<>();
+    fieldErrors.forEach(
+        fieldError -> errors.put(fieldError.getField(), fieldError.getDefaultMessage()));
+
+    ApiData<T> apiData = ApiData.<T>builder()
+        .success(false)
+        .errorCode(ErrorInfo.NOT_VALID_REQUEST.getCode())
+        .errorMessage(errors)
+        .build();
+    return ResponseEntity.ok(apiData);
+  }
+
+  public static ResponseEntity<ApiData<String>> errorFrom(ErrorInfo error) {
+    ApiData<String> apiData = ApiData.<String>builder()
+        .success(false)
+        .errorCode(error.getCode())
+        .errorMessage(error.getMessage())
+        .build();
+    return ResponseEntity.status(error.getStatusCode()).body(apiData);
+  }
+}

src/main/java/com/leets/team2/xclone/exception/ApplicationException.java

@@ -0,0 +1,14 @@
+package com.leets.team2.xclone.exception;
+
+import lombok.Getter;
+
+@Getter
+public class ApplicationException extends RuntimeException {
+
+  protected ErrorInfo errorInfo;
+
+  protected ApplicationException(ErrorInfo errorInfo) {
+    super(errorInfo.getMessage());
+    this.errorInfo = errorInfo;
+  }
+}

src/main/java/com/leets/team2/xclone/exception/ErrorInfo.java

@@ -0,0 +1,20 @@
+package com.leets.team2.xclone.exception;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import org.springframework.http.HttpStatus;
+
+@Getter
+@AllArgsConstructor
+public enum ErrorInfo {
+
+  // validation 실패
+  NOT_VALID_REQUEST(HttpStatus.BAD_REQUEST, "요청을 검증하는데 실패했습니다.", 9999),
+
+  // Member 영역
+  NO_SUCH_MEMBER(HttpStatus.NOT_FOUND, "해당 멤버를 찾을 수 없습니다.", 10001);
+
+  private final HttpStatus statusCode;
+  private final String message;
+  private final int code;
+}

src/main/java/com/leets/team2/xclone/exception/handler/GlobalExceptionHandler.java

@@ -0,0 +1,44 @@
+package com.leets.team2.xclone.exception.handler;
+
+import com.leets.team2.xclone.common.ApiData;
+import com.leets.team2.xclone.exception.ApplicationException;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.MethodArgumentNotValidException;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+@Slf4j
+public class GlobalExceptionHandler {
+
+  private static final String INTERNAL_SERVER_ERROR = "서버에 오류가 발생했습니다.\n잠시후 다시 시도해주세요.";
+
+  @ExceptionHandler(ApplicationException.class)
+  public ResponseEntity<ApiData<String>> handleApplicationException(ApplicationException e) {
+    return ApiData.errorFrom(e.getErrorInfo());
+  }
+
+  @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+  @ExceptionHandler(RuntimeException.class)
+  public String handleAnyRunTimeException(RuntimeException e) {
+    log.warn("Unexpected Error Occurred", e);
+    return INTERNAL_SERVER_ERROR;
+  }
+
+
+
+  @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
+  @ExceptionHandler(Exception.class)
+  public String handleAnyCheckedException(Exception e) {
+    log.error("Unexpected Error Occurred", e);
+    return INTERNAL_SERVER_ERROR;
+  }
+
+  @ExceptionHandler(MethodArgumentNotValidException.class)
+  public ResponseEntity<ApiData<String>> handleMethodArgumentNotValidException(MethodArgumentNotValidException e) {
+    return ApiData.validationFailure(e.getFieldErrors());
+  }
+}