feat: Error 관련 코드, 전역 예외 처리 핸들러 추가 (#5)

src/main/java/com/project/mapdagu/error/ErrorCode.java

@@ -4,12 +4,14 @@
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
 
+import static org.springframework.http.HttpStatus.*;
+
 
 @Getter
 @RequiredArgsConstructor
 public enum ErrorCode {
 
-    TOKEN_NOT_EXIST(-1000, "토큰이 존재하지 않습니다.");
+    TOKEN_NOT_EXIST(NOT_FOUND, "토큰이 존재하지 않습니다.");
 
     private final int code;
     private final String message;

src/main/java/com/project/mapdagu/error/dto/ErrorResponse.java

@@ -0,0 +1,8 @@
+package com.project.mapdagu.error.dto;
+
+public record ErrorResponse(int code, String message) {
+    public static ErrorResponse of(int code, String message){
+        return new ErrorResponse(code, message);
+    }
+
+}

src/main/java/com/project/mapdagu/error/exception/GlobalExceptionHandler.java

@@ -1,9 +1,19 @@
 package com.project.mapdagu.error.exception;
 
+import com.project.mapdagu.error.dto.ErrorResponse;
+import com.project.mapdagu.error.exception.custom.BusinessException;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.RestControllerAdvice;
 
 @Slf4j
 @RestControllerAdvice
 public class GlobalExceptionHandler {
+
+    @ExceptionHandler
+    public ResponseEntity<ErrorResponse> handle(final BusinessException e) {
+        log.info("businessException: {}", e);
+        return ResponseEntity.badRequest().body(ErrorResponse.of(e.getCode(), e.getMessage()));
+    }
 }

src/main/java/com/project/mapdagu/error/exception/custom/BusinessException.java

@@ -0,0 +1,15 @@
+package com.project.mapdagu.error.exception.custom;
+
+import com.project.mapdagu.error.ErrorCode;
+import lombok.Getter;
+
+@Getter
+public class BusinessException extends RuntimeException{
+
+    private final int code;
+
+    public BusinessException(ErrorCode errorCode) {
+        super(errorCode.getMessage());
+        this.code = errorCode.getCode();
+    }
+}