선택지 통계 조회 기능 구현

backend/src/main/java/com/votogether/exception/BadRequestException.java

@@ -0,0 +1,9 @@
+package com.votogether.exception;
+
+public class BadRequestException extends BaseException {
+
+    public BadRequestException(final ExceptionType exceptionType) {
+        super(exceptionType);
+    }
+
+}

backend/src/main/java/com/votogether/exception/BaseException.java

@@ -0,0 +1,14 @@
+package com.votogether.exception;
+
+import lombok.Getter;
+
+@Getter
+public class BaseException extends RuntimeException {
+
+    private final ExceptionType exceptionType;
+
+    public BaseException(final ExceptionType exceptionType) {
+        this.exceptionType = exceptionType;
+    }
+
+}

backend/src/main/java/com/votogether/exception/ExceptionResponse.java

@@ -0,0 +1,10 @@
+package com.votogether.exception;
+
+public record ExceptionResponse(int code, String message) {
+
+    public static ExceptionResponse from(final BaseException e) {
+        final ExceptionType exceptionType = e.getExceptionType();
+        return new ExceptionResponse(exceptionType.getCode(), exceptionType.getMessage());
+    }
+
+}

backend/src/main/java/com/votogether/exception/ExceptionType.java

@@ -0,0 +1,9 @@
+package com.votogether.exception;
+
+public interface ExceptionType {
+
+    int getCode();
+
+    String getMessage();
+
+}

backend/src/main/java/com/votogether/exception/GlobalExceptionHandler.java

@@ -0,0 +1,29 @@
+package com.votogether.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+@RestControllerAdvice
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler
+    public ResponseEntity<ExceptionResponse> handleException(final Exception e) {
+        return ResponseEntity.internalServerError()
+                .body(new ExceptionResponse(-9999, "알 수 없는 서버 에러가 발생했습니다."));
+    }
+
+    @ExceptionHandler
+    public ResponseEntity<ExceptionResponse> handleBadRequestException(final BadRequestException e) {
+        return ResponseEntity.badRequest()
+                .body(ExceptionResponse.from(e));
+    }
+
+    @ExceptionHandler
+    public ResponseEntity<ExceptionResponse> handleNotFoundException(final NotFoundException e) {
+        return ResponseEntity.status(HttpStatus.NOT_FOUND)
+                .body(ExceptionResponse.from(e));
+    }
+
+}

backend/src/main/java/com/votogether/exception/NotFoundException.java

@@ -0,0 +1,9 @@
+package com.votogether.exception;
+
+public class NotFoundException extends BaseException {
+
+    public NotFoundException(final ExceptionType exceptionType) {
+        super(exceptionType);
+    }
+
+}