📝 에러 코드 공통화 및 인터페이스 작성

pennyway-app-external-api/build.gradle

@@ -13,11 +13,10 @@ repositories {
 }
 
 dependencies {
-    implementation 'org.springframework.boot:spring-boot-starter-web:3.2.3'
-    implementation 'org.springframework.boot:spring-boot-starter-validation:3.2.3'
-
     implementation project(':pennyway-common')
     implementation project(':pennyway-domain')
     implementation project(':pennyway-infra')
 
+    implementation 'org.springframework.boot:spring-boot-starter-web:3.2.3'
+    implementation 'org.springframework.boot:spring-boot-starter-validation:3.2.3'
 }

pennyway-common/src/main/java/kr/co/pennyway/common/exception/BaseErrorCode.java

@@ -0,0 +1,46 @@
+package kr.co.pennyway.common.exception;
+
+/**
+ * 커스텀 에러 코드를 정의하기 위한 인터페이스
+ * <br>
+ * 에러 코드는 다음과 같은 형식으로 정의한다.
+ * <br>
+ * <pre>
+ * {@code
+ * @Getter
+ * @RequiredArgsConstructor
+ * public enum UserErrorCode implements BaseErrorCode {
+ *      NOT_FOUND_EMAIL(StatusCode.NOT_FOUND, ReasonCode.ACCESS_TO_THE_REQUESTED_RESOURCE_IS_FORBIDDEN, FieldCode.EMAIL, "해당 유저의 이메일이 존재하지 않습니다."),
+ *      NOT_FOUND_USER(StatusCode.NOT_FOUND, ReasonCode.ACCESS_TO_THE_REQUESTED_RESOURCE_IS_FORBIDDEN, FieldCode.ZERO, "해당 유저가 존재하지 않습니다."),
+ *
+ *      REQUIRED_EMAIL(StatusCode.UNPROCESSABLE_CONTENT, ReasonCode.REQUIRED_PARAMETERS_MISSING_IN_REQUEST_BODY, FieldCode.EMAIL, "이메일은 필수 입력값입니다."),
+ *
+ *      private final StatusCode statusCode;
+ *      private final ReasonCode reasonCode;
+ *      private final FieldCode fieldCode;
+ *      private final String message;
+ *
+ *      @Override
+ *      public CausedBy causedBy() {
+ *          return CausedBy.valueOf(statusCode, reasonCode, DomainCode.USER, FieldCode.COMMON);
+ *      }
+ *
+ *      @Override
+ *      public String getExplainError() throws NoSuchFieldError {
+ *          return message;
+ *      }
+ * }
+ * }
+ * </pre>
+ * 에러 코드는 다음과 같은 형식으로 사용한다.
+ * <pre>
+ * {@code throw new GlobalErrorException(UserErrorCode.NOT_FOUND_USER); }
+ * </pre>
+ * See Also:
+ * {@link CausedBy}, {@link StatusCode}, {@link ReasonCode}, {@link DomainCode}, {@link FieldCode}, {@link GlobalErrorException}
+ * @author YANG JAESEO
+ */
+public interface BaseErrorCode {
+    CausedBy causedBy();
+    String getExplainError() throws NoSuchFieldError;
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/CausedBy.java

@@ -0,0 +1,88 @@
+package kr.co.pennyway.common.exception;
+
+import java.util.Objects;
+import java.util.stream.Stream;
+
+/**
+ * 에러 코드를 구성하는 상세 코드
+ *
+ * @param statusCode {@link StatusCode} 상태 코드
+ * @param reasonCode {@link ReasonCode} 이유 코드
+ * @param domainCode {@link DomainCode} 도메인 코드
+ * @param fieldCode {@link FieldCode} 필드 코드
+ *
+ * - see also: {@link StatusCode}, {@link ReasonCode}, {@link DomainCode}, {@link FieldCode}
+ */
+public record CausedBy(
+    StatusCode statusCode,
+    ReasonCode reasonCode,
+    DomainCode domainCode,
+    FieldCode fieldCode
+) {
+    private static final int STATUS_CODE_MULTIPLIER = 10000;
+    private static final int REASON_CODE_MULTIPLIER = 1000;
+    private static final int DOMAIN_CODE_MULTIPLIER = 10;
+
+    public CausedBy {
+        Objects.requireNonNull(statusCode, "statusCode must not be null");
+        Objects.requireNonNull(reasonCode, "reasonCode must not be null");
+        Objects.requireNonNull(domainCode, "domainCode must not be null");
+        Objects.requireNonNull(fieldCode, "fieldCode must not be null");
+
+        if (!isValidCodes(statusCode.getCode(), reasonCode.getCode(), domainCode.getCode(), fieldCode.getCode())) {
+            throw new IllegalArgumentException("Invalid bit count");
+        }
+    }
+
+    /**
+     * CausedBy 객체를 생성하는 정적 팩토리 메서드
+     * <br/>
+     * 모든 코드의 조합으로 생성된 최종 코드는 7자리의 문자열로 구성된다.
+     * @param statusCode {@link StatusCode} 상태 코드 (3자리)
+     * @param reasonCode {@link ReasonCode} 이유 코드 (1자리)
+     * @param domainCode {@link DomainCode} 도메인 코드 (1자리 or 2자리)
+     * @param fieldCode {@link FieldCode} 필드 코드 (1자리)
+     * @throws IllegalArgumentException 전체 코드가 7자리가 아닌 경우, 혹은 각 상태 코드가 자릿수를 준수하지 않은 경우
+     * @throws NullPointerException 인자가 null인 경우
+     * @return CausedBy
+     */
+    public static CausedBy of(StatusCode statusCode, ReasonCode reasonCode, DomainCode domainCode, FieldCode fieldCode) {
+        return new CausedBy(statusCode, reasonCode, domainCode, fieldCode);
+    }
+
+    /**
+     * status code, reason code, domain code, field code를 조합하여 에러 코드를 생성한다.
+     * @return String : 7자리 정수로 구성된 에러 코드
+     */
+    public String getCode() {
+        return generateCode();
+    }
+
+    /**
+     * 에러가 발생한 이유를 반환한다.
+     * <br/>
+     * Reason은 사전에 예외 문서에 명시한 정보를 반환한다.
+     * @return String : 에러가 발생한 이유
+     */
+    public String getReason() {
+        return reasonCode.name();
+    }
+
+    private String generateCode() {
+        return String.valueOf(statusCode.getCode() * STATUS_CODE_MULTIPLIER + reasonCode.getCode() * REASON_CODE_MULTIPLIER + domainCode.getCode() * DOMAIN_CODE_MULTIPLIER + fieldCode.getCode());
+    }
+
+    private boolean isValidCodes(int statusCode, int reasonCode, int domainCode, int fieldCode) {
+        return isValidDigit(statusCode, 3) && isValidDigit(reasonCode, 1) && (isValidDigit(domainCode, 1) || isValidDigit(domainCode, 2)) && isValidDigit(fieldCode, 1);
+    }
+
+    private boolean isValidDigit(int number, long expectedDigit) {
+        return calcDigit(number) == expectedDigit;
+    }
+
+    private long calcDigit(int number) {
+        if (number == 0) return 1;
+        return Stream.iterate(number, n -> n > 0, n -> n / 10)
+            .count();
+    }
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/DomainCode.java

@@ -0,0 +1,38 @@
+package kr.co.pennyway.common.exception;
+
+/**
+ * 도메인 코드
+ * <br>
+ * 도메인 코드는 각 도메인별로 고유한 코드를 가지고 있으며, 해당 코드는 각 도메인별로 고유한 에러를 구분하기 위해 사용된다.
+ * <br>
+ * ZERO(0)는 기본 코드로 사용되며, 도메인 코드를 사용하지 않는 경우에 사용한다.
+ * <pre>
+ * ZERO 필드는 모든 BaseErrorCode를 구현하는 모든 도메인 코드에서 정의되어야 한다.
+ * {@code
+ * @RequiredArgsConstructor
+ * public enum DomainBitCode implements DomainCode {
+ *      ZERO(0),
+ *      USER(1),
+ *      PRODUCT(2),
+ *      ORDER(3);
+ *
+ *      private final int code;
+ *
+ *      @Override
+ *      public int getCode() {
+ *          return code;
+ *      }
+ *
+ *      @Override
+ *      public String getDomainName() {
+ *          return name().toLowerCase();
+ *      }
+ * }
+ * }
+ * </pre>
+ * @author YANG JAESEO
+ */
+public interface DomainCode {
+    int getCode();
+    String getDomainName();
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/FieldCode.java

@@ -0,0 +1,33 @@
+package kr.co.pennyway.common.exception;
+
+/**
+ * 도메인의 필드 코드
+ * <pre>
+ * {@code
+ * @RequiredArgsConstructor
+ * public enum UserFieldCode implements FieldCode {
+ *    ZERO(0),
+ *    ID(1),
+ *    PASSWORD(2),
+ *    NAME(3);
+ *
+ *    private final int code;
+ *
+ *    @Override
+ *    public int getCode() {
+ *      return code;
+ *    }
+ *
+ *    @Override
+ *    public String getFieldName() {
+ *      return name().toLowerCase();
+ *    }
+ * }
+ * }
+ * </pre>
+ * @author YANG JAESEO
+ */
+public interface FieldCode {
+    int getCode();
+    String getFieldName();
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/GlobalErrorException.java

@@ -0,0 +1,44 @@
+package kr.co.pennyway.common.exception;
+
+import lombok.Getter;
+
+/**
+ * 전역 에러 처리를 위한 예외 클래스
+ * <br>
+ * 전역 에러 처리를 명시적인 에러 처리로 변경하고 싶다면 다음과 같이 사용한다.
+ * <pre>
+ * {@code
+ * public class DomainErrorException extends GlobalErrorException {
+ *    private final DomainErrorCode errorCode;
+ *
+ *    public DomainErrorException(DomainErrorCode errorCode) {
+ *      super(errorCode);
+ *      this.errorCode = errorCode;
+ *    }
+ *
+ *    public CausedBy causedBy() { return errorCode.causedBy(); }
+ *    public BaseErrorCode getErrorCode() { return errorCode; }
+ * }
+ * }
+ * </pre>
+ * @author YANG JAESEO
+ */
+@Getter
+public class GlobalErrorException extends RuntimeException {
+    private final BaseErrorCode baseErrorCode;
+
+    public GlobalErrorException(BaseErrorCode baseErrorCode) {
+        super(baseErrorCode.causedBy().reasonCode().name());
+        this.baseErrorCode = baseErrorCode;
+    }
+
+    public CausedBy causedBy() {
+        return baseErrorCode.causedBy();
+    }
+
+    @Override
+    public String toString() {
+        return "GlobalErrorException(code=" + baseErrorCode.causedBy().getCode()
+                + ", message=" + baseErrorCode.getExplainError() + ")";
+    }
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/ReasonCode.java

@@ -0,0 +1,62 @@
+package kr.co.pennyway.common.exception;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+/**
+ * 에러 발생 이유 코드
+ */
+@Getter
+@RequiredArgsConstructor
+public enum ReasonCode {
+    /* 400_BAD_REQUEST */
+    INVALID_REQUEST_SYNTAX(0),
+    MISSING_REQUIRED_PARAMETER(1),
+    MALFORMED_PARAMETER(2),
+    MALFORMED_REQUEST_BODY(3),
+
+    /* 401_UNAUTHORIZED */
+    MISSING_OR_INVALID_AUTHENTICATION_CREDENTIALS(0),
+    EXPIRED_OR_REVOKED_TOKEN(1),
+    INSUFFICIENT_PERMISSIONS(2),
+    TAMPERED_OR_MALFORMED_TOKEN(3),
+
+    /* 403_FORBIDDEN */
+    ACCESS_TO_THE_REQUESTED_RESOURCE_IS_FORBIDDEN(0),
+    IP_ADDRESS_BLOCKED(1),
+    USER_ACCOUNT_SUSPENDED_OR_BANNED(2),
+    ACCESS_TO_RESOURCE_NOT_ALLOWED_FOR_USER_ROLE(3),
+
+    /* 404_NOT_FOUND */
+    REQUESTED_RESOURCE_NOT_FOUND(0),
+    INVALID_URL_OR_ENDPOINT(1),
+    RESOURCE_DELETED_OR_MOVED(2),
+
+    /* 405_METHOD_NOT_ALLOWED */
+    REQUEST_METHOD_NOT_SUPPORTED(0),
+    ATTEMPTED_TO_ACCESS_UNSUPPORTED_METHOD(1),
+
+    /* 406_NOT_ACCEPTABLE */
+    REQUESTED_RESPONSE_FORMAT_NOT_SUPPORTED(0),
+
+    /* 409_CONFLICT */
+    REQUEST_CONFLICTS_WITH_CURRENT_STATE_OF_RESOURCE(0),
+    RESOURCE_ALREADY_EXISTS(1),
+    CONCURRENT_MODIFICATION_CONFLICT(2),
+
+    /* 412_PRECONDITION_FAILED */
+    PRECONDITION_REQUEST_HEADER_NOT_MATCHED(0),
+    IF_MATCH_HEADER_OR_IF_NONE_MATCH_HEADER_NOT_MATCHED(1),
+
+    /* 422_UNPROCESSABLE_CONTENT */
+    REQUIRED_PARAMETERS_MISSING_IN_REQUEST_BODY(0),
+    VALIDATION_ERROR_IN_REQUEST_BODY(1),
+    ;
+
+    private final int code;
+
+    @Override
+    public String toString() {
+        return name();
+    }
+}

pennyway-common/src/main/java/kr/co/pennyway/common/exception/StatusCode.java

@@ -0,0 +1,30 @@
+package kr.co.pennyway.common.exception;
+
+import lombok.Getter;
+import lombok.RequiredArgsConstructor;
+
+/**
+ * HTTP 상태 코드
+ */
+@Getter
+@RequiredArgsConstructor
+public enum StatusCode {
+    SUCCESS(200),
+    CREATED(201),
+    NO_CONTENT(204),
+
+    BAD_REQUEST(400),
+    UNAUTHORIZED(401),
+    FORBIDDEN(403),
+    NOT_FOUND(404),
+    METHOD_NOT_ALLOWED(405),
+    NOT_ACCEPTABLE(406),
+    CONFLICT(409),
+    PRECONDITION_FAILED(412),
+    UNPROCESSABLE_CONTENT(422),
+
+    INTERNAL_SERVER_ERROR(500),
+    SERVICE_UNAVAILABLE(503);
+
+    private final int code;
+}