java文件内容转换为字符串

public class FileToStringUtils {
    public static String convertMultipartFileToString(MultipartFile file) throws IOException {
        if (file == null || file.isEmpty()) {
            throw new IllegalArgumentException("File cannot be null or empty");
        }

        try (BufferedReader reader = new BufferedReader(new InputStreamReader(file.getInputStream(), StandardCharsets.UTF_8))) {
            StringBuilder stringBuilder = new StringBuilder();
            String line;
            while ((line = reader.readLine()) != null) {
                stringBuilder.append(line);
                stringBuilder.append("\n");
            }
            return stringBuilder.toString();
        }
    }

}