CsvReader.java

package life.mosu.mosuserver.application.admin.util;

import life.mosu.mosuserver.application.admin.dto.ApplicationCsvInfo;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;

@Slf4j
@Component
public class CsvReader {

    private static final String CSV_DELIMITER = ",";

    public List<ApplicationCsvInfo> read(MultipartFile file) {
        List<ApplicationCsvInfo> results = new ArrayList<>();

        if (file == null || file.isEmpty()) {
            log.warn("업로드된 파일이 비어있습니다.");
            return results;
        }

        try (BufferedReader reader =
                     new BufferedReader(new InputStreamReader(file.getInputStream(), StandardCharsets.UTF_8))) {

            String line;
            boolean isHeader = true;
            int lineNumber = 0;

            while ((line = reader.readLine()) != null) {
                lineNumber++;
                if (line.isBlank()) continue;
                if (isHeader) {
                    isHeader = false;
                    continue;
                }

                try {
                    String[] values = line.split(CSV_DELIMITER, -1);
                    results.add(ApplicationCsvInfo.of(values));
                } catch (Exception e) {
                    log.error("CSV 파싱 실패 (Line {}): {}", lineNumber, e.getMessage());
                    throw new RuntimeException("CSV 파싱 오류");

                }
            }
        } catch (Exception e) {
            log.error("파일 읽기 실패: {}", e.getMessage(), e);
            throw new RuntimeException("CSV 읽기 오류");
        }

        return results;
    }
}